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1.
Zorbas YG Yarullin VL Denogradov SD Afonin VB Kakurin VK 《Biological trace element research》2002,88(2):125-138
Hypokinesia (diminished movement) induces phosphate (P) changes; however, it is not known if P change is greater in trained
than untrained subjects. Measuring P balance and P retention during hypokinesia (HK) and P load, we studied if changes in
P retention and P depletion were significantly (p<0.05) greater in trained than untrained subjects. Studies were done during a 30-d pre-HK period and a 364-d HK period. Forty
male trained and untrained healthy individuals aged 24.5±5.4 yr were chosen as subjects. All volunteers were equally divided
into four groups: trained ambulatory control subjects (TACS), trained hypokinetic subjects (THKS), untrained ambulatory control
subjects (UACS), and untrained hypokinetic subjects (UHKS). All THKS and UHKS were limited to an average walking distance
of 0.3 km/d, and TACS and UACS were on an average running distance of 9.8 and 1.8 km/d, respectively. Subjects took daily
12.7-mmol dicalcium-phosphate/kg body weight in the form of supplementation.
Negative P balance, fecal P loss, urinary P and calcium (Ca) excretion, serum P, and total Ca (Cat) levels increased significantly (p<0.05), whereas P retention, serum 1,25-dihydroxyvitamin D [1,25 (OH)2D3] and intact parathyroid hormone (iPTH) level decreased significantly (p<0.05) in THKS and UHKS when compared with their pre-HK values and their respective ambulatory controls (TACS and UACS). However,
P retention, P balance, serum, urinary, and fecal P, and serum hormone level changed significantly (p<0.05) more in THKS than UHKS. Retention of P, fecal P, urinary P and Ca loss, serum P and Cat level, P balance, 1,25(OH)2D3, and iPTH level change insignificantly (p>0.05) in TACS and UACS when compared with their pre-HK control values.
It was concluded that significant negative P balance may indicate P depletion, whereas significant P loss in spite of negative
P balance and P load may suggest P retention incapacity; however, P depletion was greater in THKS than UHKS. Clearly, P is
wasted much more in THKS than UHKS. 相似文献
2.
Zorbas YG Petrov KL Kakurin VJ Kuznetsov NA Charapakhin KP Alexeyev ID Denogradov SD 《Biological trace element research》2000,73(3):231-250
Calcium (Ca) supplements may be used to normalize Ca-balance changes but little is known about the effect of Ca supplements
on Ca balance during hypokinesia (decreased kilometers per day). The aim of this study was to evaluate the effect of daily
intakes of Ca supplements on Ca balance during hypokinesia (HK).
Studies were done during 30 d of a pre-HK period and during 364 d of a HK period. Forty male athletes aged 23–26 yr were chosen
as subjects. They were divided equally into four groups: unsupplemented ambulatory control subjects (UACS), unsupplemented
hypokinetic subjects (UHKS), supplemented hypokinetic subjects (SHKS), and supplemented ambulatory control subjects (SACS).
The SHKS and UHKS groups were kept under an average running distance of 0.7 km/d. In the SHKS and SACS groups supplemented
with 35.0 mg Ca lactate/kg body weight.
Fecal Ca loss, urinary excretion of Ca and phosphate (P), serum concentrations of ionized calcium (CaI) total Ca, P, and Ca balance, intact parathyroid hormone (iPTH) and 1,25 dihydroxyvitamin D (1,25(OH)2D), anthropometric
characteristics and peak oxygen uptake were measured. Fecal Ca excretion, urinary Ca and P excretion, serum CaI, total Ca, and P concentration, and negative Ca balanced increased significantly (p ≤ 0.01) in the SHKS and UHKS groups when compared with the SACS and UACS groups. Serum, urinary, and fecal Ca changes were
much greater and appeared much faster in the SHKS group than in the UHKS group. Serum iPTH and 1,25 (OH)2 D, body weight,
and peak oxygen uptake decreased significantly (p ≤ 0.01) in the SHKS and UHKS groups when compared with the SACS and UACS groups. In contrast, the corresponding parameters
remained stable in the SACS and UACS groups when compared with the baseline control values.
It was concluded that during prolonged HK, urinary and fecal Ca excretion and serum Ca concentration increased significantly
despite the presence of a negative Ca balance; thus, Ca supplements cannot be used to normalize negative Ca balance during
prolonged HK. 相似文献
3.
Zorbas YG Kakurin VJ Kuznetsov NA Yarullin VL Andreyev ID Charapakhin KP 《Biological trace element research》2002,85(3):211-226
Hypokinesia (diminished movement) induces significant phosphate (P) excretion; however, little is known about the P deposition
ability of the body during hypokinesia (HK). Using P loads, the aim of this study was to establish the deposition ability
of the body to retain P during prolonged HK. Studies were done during a 30-d period of pre-HK and a 364-d period of HK. Forty
male trained athletes aged 24.7 ± 8.0 yr were chosen as subjects. They were equally divided into four groups: unloaded ambulatory
control subjects (UACS), unloaded hypokinetic subjects (UHKS), loaded ambulatory control subjects (LACS), and loaded hypokinetic
subjects (LHKS). All hypokinetic subjects were limited to an average walking distance of 0.7 km/d. Loading tests with 85.0
mg of calcium phosphate/kg body weight were performed on the LACS and LHKS.
Fecal P loss, urinary calcium (Ca) and P loss, serum P, Ca, and the ionized calcium (CaI) levels increased significantly (p≤0.05) in the LHKS and UHKS groups when compared with the LACS and UACS groups, respectively. Serum intact parathyroid hormone
(iPTH) and the 1,25-dihydroxyvitamin D3 [1,25-(OH)2 D3] levels decreased significantly (p≤0.05) in the LHKS and UHKS groups when compared with the LACS and UACS groups, respectively. After the P load, significant
(p≤0.05) differences were observed between LHKS and UHKS groups regarding serum, urinary, and fecal P changes. Thus, the deposition
capacity of P decreased significantly (p≤0.05) more in the LHKS group than in the UHKS group. The deposition of P, fecal P, urinary P and Ca, serum CaI, P, Ca, 1,25-(OH)2 D3, and iPTH changed insignificantly (p>0.05) in control groups when compared with their baseline values.
It was shown that after the P load, significant differences were observed between the loaded and unloaded hypokinetic subjects
regarding serum, urinary, and fecal P values and P retention. The oral P load intensified P loss from the body. It was concluded
that the higher the P intake increased the greater P loss and the lower P deposition and thus the less likely it is for the
P load to benefit hypokinetic subjects. 相似文献
4.
Yan G. Zorbas Kirill P. Charapakin Vassil J. Kakurin Nikolai K. Kuznetsov Maxim A. Federov Vladimir K. Popov 《Biological trace element research》1999,69(2):81-98
The aim of this study was to assess the effect of a daily intake of copper supplements on negative copper balance during prolonged
exposure to hypokinesia (decreased number of kilometers per day). During hypokinesia (HK), negative copper balance is shown
by increased, not by decreased, serum copper concentration, as it happens in other situations.
Studies were done during a 30-d prehypokinetic period and a 364-d hypokinetic period. Forty male trained volunteers aged 22–26
yr with a peak oxygen uptake of 66.4 mL/min/kg and with an average of 13.7 km/d running distance were chosen as subjects.
They were equally divided into four groups: unsupplemented ambulatory control subjects (UACS), unsupplemented hypokinetic
subjects (UHKS), supplemented hypokinetic subjects (SHKS), and supplemented ambulatory control subjects (SACS). The SACS and
SHKS groups took 0.09 mg copper carbonate/kg body weight daily. The SHKS and UHKS groups were maintained under an average
running distance of 1.7 km/d, whereas the SACS and UACS groups did not experience any modifications in their normal training
routines.
During the 30-d prehypokinetic period and the 346-d hypokinetic period, urinary excretion of copper, calcium, and magnesium
and serum concentrations of copper, calcium, and magnesium were measured. Copper loss in feces and copper balance was also
determined. In both UHKS and SHKS groups, urinary excretion of copper, calcium, and magnesium and concentrations of copper,
magnesium, and calcium in serum increased significantly when compared with the SACS and UACS groups. Loss of copper in feces
was also increased significantly in the SHKS and UHKS groups when compared with the UACS and SACS groups. Throughout the study,
the copper balance was negative in the SHKS and UHKS groups, whereas in the SACS and UACS groups, the copper balance was positive.
It was concluded that a daily intake of copper supplements cannot be used to prevent copper deficiency shown by increased
copper concentration. Copper supplements also failed to prevent negative copper balance and copper losses in feces and urine
in endurancetrained subjects during prolonged exposure to HK. 相似文献
5.
Yan G. Zorbas Vassil J. Kakurin Victor B. Afonin Nikolai A. Kuznetsov Vladimir L. Yarullin Sergei D. Denogradov 《Biological trace element research》1999,70(1):1-19
Negative potassium balance during hypokinesia (decreased number of kilometers taken/day) is not based on the potassium shortage
in the diet, but on the impossibility of the body to retain potassium. To assess this hypothesis, we study the effect of potassium
loading on athletes during prolonged hypokinesia (HK).
Studies were done during 30 d of a pre-HK period and during 364 d of an HK period. Forty male athletes aged 23–26 yr were
chosen as subjects. They were divided equally into four groups: unloaded ambulatory control subjects (UACS), unloaded hypokinetic
subjects (UHKS), loaded hypokinetic subjects (LHKS), and loaded ambulatory control subjects (LACS). For the simulation of
the hypokinetic effect, the LHKS and UHKS groups were kept under an average running distance of 1.7 km/d. In the LACS and
LHKS groups, potassium loading tests were done by administering 95.35 mg KC1 per kg body weight.
During the pre-HK and HK periods and after KC1 loading tests, fecal and urinary potassium excretion, sodium and chloride excretion,
plasma potassium, sodium and chloride concentration, and potassium balance were measured. Plasma renin activity (PRA) and
plasma aldosterone concentration was also measured. Negative potassium balance increased significantly (p < -0.01) in the UHKS and LHKS groups when compared with the UACS and LACS groups. Plasma electrolyte concentration, urinary
electrolyte excretion, fecal potassium excretion, PRA, and PA concentration increased significantly (p ≤ 0.01) in the LHKS
and UHKS groups when compared with LACS and UACS groups. Urinary and fecal potassium excretion increased much more and much
faster in the LHKS group than in the UHKS group. By contrast, the corresponding parameters change insignificantly in the UACS
and LACS groups when compared with the base line control values.
It was concluded that urinary and fecal potassium excretion increased significantly despite the presence of negative potassium
balance; thus, negative potassium balance may not be based on potassium shortage in the diet because of the impossibility
of the body to retain potassium during HK. 相似文献
6.
Zorbas YG Kakurin VJ Afonin VB Charapakhin KP Denogradov SD 《Biological trace element research》2000,78(1-3):93-112
Electrolyte supplements may be used to prevent changes in electrolyte balance during hypokinesia (diminished movement). The
aim of this study was to measure the effect of potassium (K) supplements on K balance during prolonged hypokinesia (HK).
Studies were done during 30 d of a pre-HK period and during 364 d of an HK period. Forty male athletes aged 25.1±4.4 yr were
chosen as subjects. They were divided equally into four groups: unsupplemented ambulatory control subjects (UACS), unsupplemented
hypokinetic subjects (UHKS), supplemented hypokinetic subjects (SHKS) and supplemented ambulatory control subjects (SACS).
The SHKS and UHKS groups were kept under an average walking distance of 0.7 km/d. The SACS and SHKS groups were supplemented
daily with 50.0 mg elemental potassium chloride (KCl) per kilogram body weight.
The K balance, fecal K excretion, urinary K, sodium (Na), and chloride (Cl) excretion, plasma K, Na, and Cl concentration,
plasma renin activity (PRA) and plasma aldosterone (PA) concentration, anthropometric characteristics and peak oxygen uptake
were measured. Negative K balance, fecal K excretion, urinary K, Na, and Cl excretion, plasma K, Na, and Cl concentration,
and PRA and PA concentration increased significantly (p≤0.01), whereas body weight and peak oxygen uptake decreased significantly in the SHKS and UHKS groups when compared with
SACS and UACS groups. However, the measured parameters changed much faster and much more in SHKS group than UHKS group. By
contrast, K balance, fecal, urinary, and plasma K, plasma hormones, body weight, and peak oxygen uptake did not change significantly
in the SACS and UACS groups when compared with the baseline control values.
It was concluded that prolonged HK induces a significant negative K balance associated with increased plasma K concentration
and urinary and fecal K excretion. However, negative K balance appeared much faster and was much greater in the SHKS group
than UHKS group. Thus, K supplementation was not effective in preventing negative K balance during prolonged HK. 相似文献
7.
Yan G. Zorbas Andrei G. Kakurin Nikolai K. Kuznetsov Maxim A. Federov Yuri Y. Yaroshenko 《Biological trace element research》1998,63(2):149-166
The aim of this study was to evaluate the effect of magnesium (Mg) loading (10.0 mg Mg/kg body wt) and daily Mg supplements
(5.0 mg Mg/kg body wt) on Mg deficiency shown by increased and not by decreased serum Mg concentration during hypokinesia
(decreased km number/d).
The studies were done during 30 d of prehypokinesia and 364 d of hypokinesia (HK) periods. Forty endurance-trained volunteers
aged 22–26 yr with a peak VO2 max of 66.3 mL·kg−1 min−1 and with an average 15.0 km/d running distance were chose as subjects. They were equally divided into four groups:
The SHKS and SACS groups took daily 5.0 mg elemental Mg/kg body wt and subjected to Mg loading (10.0 mg Mg/kg body wt). Both
the SHKS and UHKS groups were maintained under an average running distance of 4.7 km/d, whereas the SACS and UACS groups did
not experience any modifications to their normal training routines and diets.
During the prehypokinetic and hypokinetic periods, excretion of Mg in feces and urine, concentration of Mg in serum, and Mg
balance were measured. urinary and serum sodium (Na), potassium (K), and calcium (Ca) were also determined. In both SHKS and
UHKS groups, fecal Mg loss, urinary excretion of electrolytes, and serum concentrations of electrolytes increased significantly
(p≤0.05) when compared with the SACS and UACS groups. During Mg loading tests, urinary and fecal Mg excretion was also greater
in the SHKS and UHKS groups than in the SACS and UACS groups. Throughout the study, Mg balance was negative in the SHKS and
UHKS groups, whereas in the SACS and UACS groups, Mg balance was positive.
It was concluded that significant losses of Mg occurred in the presence of negative Mg balance and Mg deficiency in endurance-trained
subjects during prolonged exposure to HK, daily mg supplements, and Mg loading tests. This suggests that Mg is not entering
or being retaining by the bones and cells of many tissues where most Mg is deposited normally, resulting in Mg deficiency
as was shown by the increased serum Mg concentration. 相似文献
1. | Unsupplemented ambulatory control subjects (UACS). |
2. | Unsupplemented hypokinetic subjects (UHKS). |
3. | Supplemented hypokinetic subjects (SHKS). |
4. | Supplemented ambulatory control subjects (SACS). |
8.
Zorbas YG Kakurin VJ Kuznetsov NA Yarullin VL Andreyev ID Charapakhin KP 《Biological trace element research》2002,85(1):1-22
Hypokinesia (diminished movement) induces significant potassium (K) changes; however, little is known about K deposition and
deficiency during hypokinesia (HK). Using K supplements during and after HK, the aim was to establish body K deposition and
K deficiency during HK. Studies were done during the pre-HK period of 30 d, HK period of 364 d, and post-HK period of 30 d.
Forty male trained athletes aged 24.9 ± 8.0 y were chosen as subjects. They were equally divided into four groups: unsupplemented
active control subjects (UACS), unsupplemented hypokinetic subjects (UHKS), supplemented active control subjects (SACS), and
supplemented hypokinetic subjects (SHKS). Hypokinetic subjects were limited to an average walking distance of 0.7 km/d. Control
subjects ran an average distance of 11.6 km/d. The SHKS and SACS groups took 95.0 mg elemental K/kg body weight daily.
Fecal K excretion, urinary sodium (Na) and K excretion, plasma K and Na levels, plasma renin activity (PRA), plasma aldosterone
(PA), food and fluid intake, and physical characteristics were measured. During HK, fecal K loss, urinary K and Na loss, and
plasma K, Na, PRA, and PA levels increased significantly (p ≤ 0.05), whereas during the initial days of post-HK, the levels of the measured parameters decreased significantly (p ≤ 0.05) in the SHKS and UHKS groups as compared with the SACS and UACS groups, respectively. During HK, body weight, body
fat, peak oxygen uptake, food and fluid intake decreased significantly (p ≤ 0.05), whereas during the initial days of post-HK period remained significantly (p ≤ 0.05) depressed and fluid intake increased in SHKS and UHKS groups when compared with the SACS and UACS groups, respectively.
However, during HK and post-HK plasma, urinary, and fecal K changed significantly (p ≤ 0.05) more in the SHKS group than in the UHKS group. The deposition of K was significantly (p ≤ 0.05) lower and K deficiency much higher in the SHKS group than in the UHKS group. Fecal K loss, urinary K and Na loss,
plasma K, Na, PRA, and PA levels, body weight, body fat, peak oxygen uptake, and food and fluid intake did not change significantly
in the SACS and UACS when compared with their baseline control values.
It was shown that plasma K concentration and urinary and fecal K excretion increased during HK and decreased significantly
(p ≤ 0.05) during post-HK. post-HK. Oral K supplements did not influence plasma or fecal and urinary K either during HK or post-HK.
It was concluded that the low plasma K level and fecal and urinary K loss during post-HK may indicate the presence of K deficiency,
and increased K in plasma, urine, and feces during HK and in the presence of K deficiency may suggest the body’s inability
to retain K during HK. 相似文献
9.
Zorbas YG Kakurin VJ Denogratov SD Yarullin VL Deogenov VA 《Biological trace element research》2001,80(3):201-219
Hypokinesia (HK) (diminished movement) induces significant electrolyte changes, but little is known about the effect of periodic
hypokinesia (PHK) on minerals. The aim of this study was to measure the effect of PHK and continuous hypokinesia (CHK) on
urinary and serum electrolytes. Studies were done during a 30-d period of prehypokinesia (HK) and during 364 d of PHK and
CHK periods. Thirty male athletes aged 24.6±7.7 yr were chosen as subjects. They were equally divided into three groups: unrestricted
ambulatory control subjects (UACS), continuously hypokinetic subjects (CHKS), and periodically hypokinetic subjects (PHKS).
The UACS group experienced no changes in the daily activities and regular training and they were maintained under an average
running distance of 11.7 km/d. The CHKS group was limited to an average walking distance of 0.7 km/d; and the PHKS group was
limited to an average walking distance of 0.7 and running distance of 11.7 km/d for 5 d and 2 d/wk, respectively, for a period
of 364 d.
Urinary and serum phosphate (P), calcium (Ca), sodium (Na) and potassium (K), serum intact parathyroid hormone (iPTH), calcitonin
(CT), plasma renin activity (PRA) and aldosterone (PA) levels, food and water intakes, and physical characteristics were measured.
Urinary P, Ca, Na, and K loss, serum Ca, P, Na, and K, and PRA and PA values increased significantly (p≤0.01), whereas serum iPTH and CT levels decreased significantly (p≤0.01) in the PHKS and CHKS groups when compared with the UACS group. However, significant (p≤0.01) differences were observed between PHKS and CHKS groups regarding urinary and serum electrolytes, serum and plasma hormones.
Food and water intakes, body weight, body fat, and peak oxygen uptake decreased significantly (p ≤ 0.01) in the CHKS group when compared with PHKS and UACS groups. Food and fluid intakes, body fat, and body weight increased
significantly (p≤0.01), whereas peak oxygen uptake remained significantly (p≤0.01) higher in the PHKS group when compared with the CHKS group. Serum and urinary minerals, serum hormones, food and fluid
intakes, and physical characteristics did not change significantly (p>0.01) in the UACS group when compared with their baseline control values.
It was shown that both PHK and CHK induce significant serum and urinary electrolyte changes. However, urinary and serum electrolyte
changes were significantly (p≤0.01) greater during PHK than CHK. It was concluded that the greater the stability of muscular activity, the smaller the
serum and urinary electrolyte changes during prolonged HK. 相似文献
10.
Zorbas YG Kakurin VJ Afonin VB Charapakhin KP Yarullin VL Deogenov VA 《Biological trace element research》2000,76(2):113-131
Hypokinesia (diminished movement) induces significant calcium (Ca) changes, but little is known about the effect of hypokinesia
(HK) on Ca deficiency. Measuring Ca changes during and after HK the aim of this study was to determine Ca deficiency during
prolonged HK.
Studies were done on 12 male Macaca mulatta (rhesus monkeys) aged 3–5 yr (5.58–6.42 kg) during a 90-d pre-HK period, a 90-d HK period, and a 15-d post-HK period. Monkeys
were equally divided into two groups: vivarium control monkeys (VCM) and hypokinetic monkeys (HKM). Hypokinetic monkeys were
kept in small individual cages that restricted their movements in all directions without hindering food and water intakes.
Urinary, fecal, and serum Ca, urinary and serum magnesium (Mg) and phosphate (P), serum intact parathyroid hormone (iPTH),
and calcitonin (CT) concentration, body weight, food intake, fluid consumed and eliminated in urine were measured. During
the HK period, fecal Ca loss, urinary Ca, P, and Mg excretion, fluid elimination, and serum P, Ca, and Mg concentration increased
significantly (p≤0.01), whereas serum iPTH and CT concentration, food and fluid intakes, and body weight decreased significantly (p≤0.01) in the HKM group when compared with the VCM group. During the initial days of the post-HK period, serum Ca, Mg, and
P concentration, fecal Ca loss, urinary Ca, Mg, and P excretion, and fluid elimination decreased significantly (p≤0.01), whereas fluid intake increased significantly (p≤0.01) in the HKM group when compared with the VCM group. Food intake, body weight, and serum iPTH and CT concentrations remained
significantly (p≤0.01) depressed in the HKP group when compared with the VCM; however, they increased as the duration of the post-HK period
increased. By contrast, the corresponding parameters remained stable in the VCM group when compared with the baseline control
values.
It was shown that fecal and urinary Ca loss and serum Ca concentration increases significantly during HK, whereas during post-HK
fecal, urinary, and serum Ca decreases significantly. It was concluded that significant decrease of serum, urinary, and fecal
Ca during post-HK may suggest the presence of Ca deficiency during prolonged HK. 相似文献
11.
Yan G. Zorbas Youri F. Federenko Konstantin A. Naexu 《Biological trace element research》1996,53(1-3):95-112
The objective of this investigation was to determine whether urinary and plasma potassium changes developed during prolonged
hypokinesia (HK) (decreased number of km/d) in endurance-trained subjects could be minimized or reversed with a daily intake
of fluid and salt supplementation (FSS). The studies were performed on 30 endurance-trained male volunteers aged 23–26 yr
with an average peak oxygen uptake of 65 mL/kg min during 364 d of HK. All volunteers were on an average of 13.8 km/d prior
to their exposure to HK. All volunteers were randomly divided into three groups: 10 volunteers were placed continuously under
an average of 14.0 km/d (control subjects), 10 volunteers were subjected continuously to an average of 2.7 km/d (unsupplemented
hypokinetic subjects), and 10 volunteers were submitted continuously to an average of 2.7 km/d, and consumed daily an additional
amount of 0.1 g sodium chloride (NaCl)/kg body wt and 30 mL water/kg body wt (supplemented hypokinetic subjects). During the
prehypokinetic period of 60 d and during the hypokinetic period of 364 d, potassium loading tests were performed with 1.5–1.7
mEq potassium chloride/kg body wt, and potassium, sodium, and chloride excretion in urine and potassium, sodium, and chloride
in plasma were determined. In the unsupplemented hypokinetic volunteers, urinary excretion of electrolytes and concentrations
of electrolytes in plasma increased significantly as compared to the control and supplemented hypokinetic groups of volunteers.
It was concluded that daily intake of fluid and salt supplementation had a favorable effect on regulation of urinary and plasma
potassium changes in trained subjects during prolonged HK. 相似文献
12.
Kakuris VJ Tsiamis CB Deogenov VA Peskaratos JG 《Physiological chemistry and physics and medical NMR》2004,36(2):109-121
The objective of this study was to show that prolonged restriction of motor activity (hypokinesia) could reduce phosphate (P) deposition and contribute to P loss with tissue P depletion. To this end, measurements were made of tissue P content, P absorption, plasma P levels, urinary and fecal P excretion of rats during and after hypokinesia (HK) and daily phosphate supplementation. Studies were conducted on male Wistar rats during a pre-hypokinetic period, a hypokinetic period and a post-hypokinetic period. All rats were equally divided into four groups: unsupplemented vivarium control rats (UVCR), unsupplemented hypokinetic rats (UHKR), supplemented vivarium control rats (SVCR) and supplemented hypokinetic rats (SHKR). Bone and muscle P content, plasma intact parathyroid hormone (iPTH) levels, P absorption, plasma P levels and urinary and fecal P excretion did not change in SVCR and UVCR compared with their pre-HK values. During HK, plasma P levels, urinary and fecal P excretion increased significantly (p<0.05) while muscle and bone P content, P absorption and plasma iPTH levels decreased significantly (p<0.05) in SHKR and UHKR compared with their pre-HK values and the values in their respective vivarium controls (SVCR and UVCR). During the initial 9-days of post-HK, plasma, urinary and fecal P levels decreased significantly (p<0.05), and plasma iPTH levels, muscle and bone P levels remained significantly (p<0.05) depressed in hypokinetic rats compared with their pre-HK values and the values in their respective vivarium control rats. By the 15th day, these values approached the control values. During HK and post-HK, changes in P absorption, plasma iPTH levels, and P levels in muscle, bone, plasma, urine and feces were significantly (p<0.05) greater in SHKR than in UHKR. Decreased tissue P content with increased P loss in animals receiving and not receiving P supplementation demonstrates decreased P deposition during HK. Higher P excretion with lower tissue content in SHKR and UHKR demonstrates that P deposition is decreased more with P supplementation than without. Because SHKR with a lower tissue P content showed higher P excretion than UHKR it was concluded that the risk of decreased P deposition with greater tissue P depletion is inversely related to P intake, that is, the higher the P intake the greater the risk for decreased P deposition and the greater tissue P depletion. It was shown that P (regardless of the intensity of its tissue depletion) is lost during HK unless factors contributing to the decreased P deposition are partially or totally reversed. It was concluded that dissociation between (decreased) tissue P content and (increased) P uptake indicates decreased P (absorption and) deposition as the main mechanisms of tissue P depletion during prolonged HK. 相似文献
13.
Yan G. Zorbas Youri F. Federenko Konstantin A. Naexu 《Biological trace element research》1994,41(3):253-267
The objective of this investigation was to determine the effect of daily intake of fluid and salt supplementation (FSS) on
increased urinary losses of microelements that developed during hypokinesia (decreased number of walking steps/d). The studies
were performed on 30 endurance-trained male volunteers aged 23–26 yr, with an averaged maximum oxygen uptake of 65 mL/kg/min
during 364 d of hypokinesia (HK). All volunteers were divided into three equal groups: Ten volunteers were placed continuously
under an average of 10,000 running steps/d (14.2 km/d) (control subjects), ten volunteers subjected continuously to HK without
the use of FSS (hypokinetic subjects), and ten volunteers were continuously submitted to HK and consumed daily FSS (hyperhydrated
subjects). For the simulation of the hypokinetic effect the hypokinetic and hyperhydrated volunteers were kept under an average
of 3,000 walking steps/d (2.7 km/d) for 364 d. Prior to their exposure to HK the volunteers were on an average of 10,000 running
steps/d (14.2 km/d). During the prehypokinetic period of 60 d and during the hypokinetic period of 364 d were determined renal
excretion of microelements responses of endurance-trained volunteers. In the hyperhydrated volunteers urinary excretion of
iron, zinc, copper, manganese, cobalt, nickel, lead, tin, chromium, aluminum, molybdenum, and vanadium decreased, whereas
in the hypokinetic volunteers it increased significantly. It was concluded that chronic hyperhydration may be used to attenuate
urinary excretion of microelements in endurance-trained volunteers during prolonged restriction of muscular activity. 相似文献
14.
Yan G. Zorbas Vassili G. Andreyev Grigori E. Veremtsov Youri N. Yaroshenko 《Biological trace element research》1997,58(1-2):103-116
The objective of this investigation was to determine whether a plentiful magnesium (Mg2+) supplementation might be used to normalize or prevent Mg deficiency. This is manifested by increased rather than decreased serum Mg2+ concentration as is observed during prolonged hospitalization, which is developed during prolonged hypokinesia (HK) (decreased motor activity). Eighty male Wistar rats with an initial body weight of 370–390 g were used to perform the studies: They were equally divided into four groups:
- Unsupplemented control animals (UCA);
- Supplemented control animals (SCA);
- Unsupplemented hypokinetic animals (UHA); and
- Supplemented hypokinetic animals (SHA).
15.
Rigorous bed rest (RBR) induces significant electrolyte changes, but little it is not known about the effect of acute bed
rest (ABR) (i.e., abrupt confinement to a RBR). The aim of this study was to measure urinary and plasma electrolyte changes
during ABR and RBR conditions.
The studies were done during 3 d of a pre-bed-rest (BR) period and during 7 d of an ABR and RBR period. Thirty male trained
athletes aged, 24.4 ± 6.6 yr were chosen as subjects. They were divided equally into three groups: unrestricted ambulatory
control subjects (UACS), acute-bed-rested subjects (ABRS), and rigorous-bed-rested subjects (RBRS). The UACS group experienced
no changes in professional training and daily activities. The ABRS were submitted abruptly to a RBR regimen and without having
any prior knowledge of the exact date and time when they would be subjected to an RBR regimen. The RBRS were subjected to
an RBR regime on a predetermined date and time known to them from the beginning of the study.
Sodium (Na), potassium (K), magnesium (Mg), calcium (Ca), and phosphate (P) in plasma and urine, plasma renin activity (PRA)
and plasma aldosterone (PA), physical characteristics, peak oxygen uptake, and food and water intakes were measured. Urinary
Na, K, Ca, Mg, and P excretion and plasma Na, K, Mg, Ca, and P concentration, PRA, and PA concentration increased significantly
(p ≤ 0.01), whereas body weight, peak oxygen uptake, and food and water intakes decreased significantly in the ABRS and RBRS
groups when compared with the UACS group. However, urinary and plasma Na, K, Mg, P, and Ca, PRA, and PA values increased much
faster and were much greater in the ABRS group than in the RBRS group. Plasma and urinary Na, K, Ca, Mg, and P, PRA and PA
levels, food and water intakes, body weight, and peak oxygen uptake did not change significantly in the UACS group when compared
with its baseline control values.
It was shown that RBR and ABR conditions induce significant increases in urinary and plasma electrolytes; however, urinary
and plasma electrolyte changes appeared much faster and were much greater in the ABRS group than the RBRS group. It was concluded
that the more abruptly motor activity is ended, the faster and the greater the urinary and plasma electrolyte change. 相似文献
16.
Yan G. Zorbas Youri F. Federenko Konstantin A. Naexu 《Biological trace element research》1996,54(3):251-271
The objective of this investigation was to determine fluid electrolyte changes after water-loading tests and during hypokinesia
(decreased number of km taken per day) and daily intake of fluid and salt supplementation (FSS). The studies during hypokinesia
(HK) were performed for 364 d on 30 endurance-trained male volunteers in the age range of 23–26 yr, with an average peak oxygen
uptake, POU, of 64 mL/kg/min. All volunteers were divided into three equal groups: 10 volunteers were placed on a continuous
regime of exercise of 14.4 km/d and served as control subjects (CS); 10 volunteers were submitted to continuous HK without
FSS and were considered as the unsupplemented hypokinetic subjects (UHS); and 10 volunteers were under continuous HK and FSS
and were considered as the supplemented hypokinetic subjects (SHS). For the simulation of the hypokinetic effect, the UHS
and SHS groups were kept continuously under an average of 2.7 km/d for the duration of the study. Prior to exposure to HK,
the two groups of volunteers were on the same exercise regime as the control group. During a 60-d preexperimental period and
during the remainder of the study, water-loading tests with a water load of 20 mL/kg body wt/min were performed, and urinary
and plasma electrolytes (sodium, potassium, calcium, and magnesium) were measured. In the SHS group, urinary excretion of
electrolytes and plasma electrolyte content decreased, while in the UHS these values increased after water loading tests and
during HK. Based on the obtained data, it is concluded that chronic hyperhydration may be used to prevent or minimize urinary
and plasma electrolyte changes in endurance-trained volunteers after water-loading tests and during prolonged restriction
of muscular activity. 相似文献
17.
Yan G. Zorbas Youri F. Federenko Konstantin A. Naexu 《Biological trace element research》1995,48(1):51-65
The purpose of this investigation was to determine whether negative phosphate balance, which is developed during hypokinesia (a decreased number of walking steps/d) could be reversed with daily supplementation with phosphate, fluid, and salt (FSS). The studies on hypokinesia (HK) were performed for 364 d on 30 endurance-trained male volunteers in the age range of 23–26 yr, with an average maximum oxygen uptake, MOU, of 65 mL/kg min. All subjects were divided into three equal groups: Ten volunteers were placed on a continuous regime of exercise of 14.4 kmJd at 10,000 steps/d and served as controls. Ten volunteers were subject to continuous HK without FSS and were considered as the hypokinetic subjects (HS). The remaining subjects were under continuous HK and FSS and were considered as the hypokinetic, hyperhydrated subjects (HHS). The three groups were on a diet that averaged 2620 cal/d and contained 1.7 g calcium, 1.6 g phosphate, and 5.6 g sodium chloride. For simulation of the hypokinetic effect, the HS and HHS groups were kept continuously under 2.9 km/d (3000 walking steps/d) for the duration of the study. Prior to exposure to HK, all volunteers were on the same exercise regime as the controls. During a 60-d pre-HK period and during the remainder of the study, phosphate-loading tests, urinary and plasma phosphate concentrations were performed in all subjects. In the HHS group, plasma phosphate concentration and urinary excretion of phosphate were decreased, while in the HS group these values increased after phosphate loading. Based on our results, we concluded that chronic hyperhydration and phosphate supplementation may be used to minimize phosphate losses in endurance-trained volunteers during prolonged restriction of muscular activity. 相似文献
18.
Zorbas YG Kakurin VJ Denogradov SD Luzhkov SH Neofitov AC 《Biological trace element research》2002,90(1-3):155-173
Hypokinesia (diminished movement) induces muscle mineral depletion. However, the mechanism of muscle mineral depletion during
hypokinesia (HK) remains unknown. Measuring electrolyte retention and electrolyte values in muscle, plasma, and urine during
and after HK, the aim of this study was to discover if HK could depress mineral retention and lead to muscle mineral depletion.
Studies were done on 204 13-wk-old male Wistar rats (370–390 g) during 10 d pre-HK period, 98 d HK period, and 15 d post-HK
period. Rats were equally divided into two groups: vivarium control rats (VCR) and hypokinetic rats (HKR). All hypokinetic
rats were kept for 98 d in small individual cages, which restricted their movements in all directions without hindering food
and water intakes. All control rats were housed for 98 d in individual cages under vivarium control conditions. Both groups
of rats were pair-fed.
During the HK period skeletal muscle sodium (Na), potassium (K), magnesium (Mg), calcium (Ca), and water content and electrolyte
retention decreased significantly (p < 0.05), while urinary and plasma electrolyte levels increased significantly (p < 0.05) in HKR compared with their pre-HK values and their respective VCR. During the initial days of the post-HK period,
mineral retention increased significantly (p < 0.05), plasma and urinary electrolyte level decreased significantly (p < 0.05), while muscle electrolyte and water content remained significantly (p < 0.05) depressed in HKR compared with VCR. Muscle mineral and water content, electrolyte retention, plasma, and urinary
electrolyte values did not change in VCR compared with their pre-HK values.
It was concluded that during HK decreased muscle mineral content may suggest muscle mineral depletion, while increased urinary
electrolyte loss and muscle mineral depletion may demonstrate reduced mineral retention. Reduced electrolyte excretion and
depressed muscle mineral content during post-HK may indicate skeletal muscle mineral depletion during HK. Dissociation between
electrolyte retention and muscle mineral depletion may demonstrate the presence of decreased electrolyte retention as the
mechanism of muscle electrolyte depletion during prolonged HK. 相似文献
19.
Claybaugh J. R.; Pendergast D. R.; Davis J. E.; Akiba C.; Pazik M.; Hong S. K. 《Journal of applied physiology》1986,61(1):7-15
The roles of antidiuretic hormone (ADH) and aldosterone in the elicited diuretic responses of trained and untrained men to seated, supine, and head-out water immersed conditions were studied. Volunteers were comprised of groups of six untrained individuals, six trained swimmers, and six trained runners. Each subject underwent three protocols, six hours in a seated position, supine position, or immersion (35 degrees C water). The last two protocols were preceded and followed by 1 h of seated position. After 10 h of fasting, 0.5% body wt of water was drunk. One hour later the trained groups had higher urine osmolalities (P less than 0.05) and urinary excretion rates of ADH (P less than 0.05) and lower urine flow rates (P less than 0.05) than untrained subjects. Throughout the sitting protocol, urinary ADH was also higher in both trained groups (P less than 0.05). Both supine posture and immersion resulted in significant decreases in urinary ADH in the untrained subjects (P less than 0.05) but no changes wer noted in swimmers and only during the second hour of immersion in the runners (P less than 0.05). The natriuresis and kaliuresis were greater during immersion than in the supine position but plasma renin activity, measured only in trained groups, and plasma aldosterone, measured in the untrained group, were decreased similarly with both protocols. The increases in urinary sodium excretion and urine flow rate were lower in trained than untrained subjects during the supine and immersion protocols (P less than 0.05). The data are compatible with an increased osmotic but decreased volume sensitivity of ADH control in trained men. 相似文献
20.
Zorbas YG Kakurin VJ Afonin VB Denogradov SD Yarullin VL 《Biological trace element research》2002,86(3):203-216
Hypokinesia (diminished movement) induces significant magnesium (Mg) changes; however, little is known about Mg deposition and Mg depletion during HK. Measuring the Mg level in some tissues during HK and post-HK and Mg supplement, we aimed to establish Mg deposition and Mg depletion during prolonged HK. Studies were done on 408, 13-wk-old male Wistar rats (370-390 g) for a 15-d pre-HK period, a 98-d HK period, and a 15-d post-HK period. Rats were equally divided into four groups: unsupplemented vivarium control rats (UVCR), unsupplemented hypokinetic rats (UHKR), supplemented vivarium control rats (SVCR), and supplemented hypokinetic rats (SHKR). Both UHKR and SHKR were kept in small individual cages. The SVCR and SHKR took 53 mg Mg/d. During the HK period, plasma, urinary, and fecal Mg levels increased significantly (p < or = 0.05), whereas during the post-HK period Mg deposition, muscle and bone Mg content decreased significantly (p < or = 0.05) in UHKR and SHKR when compared with their pre-HK values and their respective vivarium controls (UVCR and SVCR). During the initial days of the post-HK period, plasma, urinary, and fecal Mg levels decreased significantly (p < or = 0.05), whereas during the post-HK period Mg deposition, muscle and bone Mg content remained significantly (p < or = 0.05) depressed in UHKR and SHKR when compared with UVCR and SVCR, respectively. However, during the HK period and post-HK period Mg deposition, bone, muscle, plasma, urinary, and fecal Mg levels changed significantly (p < or = 0.05) more in SHKR than UHKR. By contrast, during the HK period and post-HK period. Mg deposition, muscle, bone, plasma, urinary, and fecal Mg values change insignificantly (p > 0.05) in UVCR and SVCR when compared with their pre-HK values. It was concluded that reduced muscle, bone, plasma, urinary, and fecal Mg during post-HK and Mg supplement may demonstrate Mg depletion, whereas higher Mg loss during HK despite reduced muscle and bone Mg and Mg depletion might demonstrate Mg deposition incapacity during HK. 相似文献