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1.
Sampathkumar R Balasubramanyam M Tara C Rema M Mohan V 《Molecular and cellular biochemistry》2006,282(1-2):169-176
Objective: Although recent studies link altered cellular redox state to protein dysfunction in various disease-states, such associations
are least studied in clinical diabetes. Therefore, this study assessed the levels of reduced glutathione (GSH) and Na+/K+ ATPase activities in type 2 diabetic patients with and without microangiopathy. Methods: The study group comprised of a total of 160 subjects, which included non-diabetic healthy controls (n = 40) and type 2 diabetic patients without (n = 60) and with microangiopathy (n = 60), defined as presence of retinopathy with or without nephropathy. Erythrocyte Na+/K+ ATPase activity and GSH levels were estimated spectrophotometrically and fluorometry was used to determine the plasma thiobarbituric
acid reactive substances (TBARS) and serum advanced glycation end products (AGEs). Results: GSH levels in diabetic subjects without (4.8± 0.15 μmol/g Hb) and with microangiopathy (5.2± 0.14 μmol/g Hb) were significantly
lower (p < 0.001) compared to control subjects (6.3± 0.14 μmol/g Hb). Erythrocyte Na+/K+ ATPase activity was significantly reduced (p < 0.001) in diabetes subjects with (272± 7 nmol Pi/mg protein/h) and without microangiopathy (304 ± 8) compared to control
(374 ± 6) subjects. TBARS were significantly higher (p < 0.001) in diabetes subjects with (10.65± 0.81 nM/ml) and without microangiopathy (9.90± 0.5 nM/ml) compared to control
subjects (5.18± 0.18 nM/ml). Advanced glycation end product levels were also significantly (p < 0.001) elevated in diabetic subjects with microangiopathy (8.2± 1.8 AU) when compared to diabetes subjects without microangiopathy
(7.0± 2.0 AU) and control subjects (4.6± 1.9 AU). On multivariate regression analysis, GSH levels showed a positive association
with the Na+/K+ ATPase activity and negative association with TBARS and AGE levels. Conclusion: Hypoglutathionemia and increased oxidative stress appears to be early biochemical aberrations in diabetes, and through protein
alterations, oxidative stress and redox modifications may contribute to pathogenesis of diabetic microangiopathy. 相似文献
2.
Jerome Honnorat Michele Accominotti Christiane Broussolle Andree-Carole Fleuret Jean-Jacques Vallon Jacques Orgiazzi 《Biological trace element research》1992,32(1-3):311-316
Zinc status was assessed in 53 diabetic patients: 18 insulin-dependent diabetic patients (IDDM), 22 noninsulin-dependent diabetic
patients (NIDDM) treated with oral antidiabetic agents, and 13 insulin-treated, noninsulin-dependent diabetic patients (IRDM).
Plasma zinc concentrations were in the usual range for healthy subjects in these three groups (15.3±0.9 μmol/L). Urinary zinc
excretions were elevated in the IDDM group (18.3±4.1 μmol/24 h;p<0.01 vs normal) and in the NIDDM group (17.5±3.5 μmol/24 h;p<0.01 vs normal), but normal in the IRDM group (11.3±2.4 μmol/24 h). In 14 NIDDM patients treated with transient continuous
sc insulin injections, urinary zinc decreased from 16.5±2.2 μmol/24 h before insulin treatment to 11.5±0.3 μmol/24 h after
insulin treatment without any modification in plasma zinc concentrations. 相似文献
3.
Ahuva Golik Nathan Cohen Yoram Ramot Joseph Maor Rita Moses Joshua Weissgarten Yuval Leonov David Modai 《Biological trace element research》1993,39(2-3):171-175
Zinc status was assessed in patients with type II diabetes mellitus and congestive heart failure (CHF). Three groups of patients
were enrolled into the study: Group 1: 15 patients with type II diabetes mellitus and CHF; Group 2: 20 patients with isolated
type II diabetes mellitus; and Group 3: nine patients with isolated CHF. Twenty-four-hour urine was measured for creatinine,
protein, and zinc, and blood was drawn for creatinine, proteins, liver enzymes, hemoglobin A1c, and zinc. Insulin treatment and hemoglobin A1c were comparable in the diabetic patients of groups 1 and 2, but group 1 was also treated with captopril and diuretics like
the CHF patients of group 3. Plasma zinc levels were statistically similar in all three groups, but urinary zinc excretion
(μmol/24 h) and urinary zinc: creatinine (μmol/mmol) ratio were significantly higher in the type II diabetics and CHF group
(27.2±1.5; 1.69±0.6, respectively) compared to the diabetic patients alone (19.4±0.76; 0.97±0.3, respectively) and the CHF
patients (9.7±0.3; 0.62±0.3, respectively). Patients with type II diabetes mellitus and CHF were treated with higher doses
of captopril than the CHF patients (56.25±24 mg vs 18.8±11 mgP<0.05). Thus, patients with type II diabetes mellitus and CHF excrete larger amounts of zinc, which may eventually lead to
zinc deficiency. 相似文献
4.
Tubek S 《Biological trace element research》2006,114(1-3):127-133
Increased or unchanged urinary zinc excretion has been reported in hypertension. In the present article, this observation
was confirmed in a group of 10 untreated hypertensive patients of both sexes that had no diabetes or obesity. The 24-h zinc
excretion was significantly different between the patients: 7.46±3.01 μmol and healthy controls: 5.19±2.19 μmol (p<0.025). After a 1-mo treatment with 4 mg perindopril per day, a decrease of urinary zinc was observed until it reached levels
not significantly different from those of the healthy controls (5.98±2.13 μmol). The decrease was significantly different
from that of the pretreatment values (p<0.05). 相似文献
5.
Bhaskar JJ Shobha MS Sambaiah K Salimath PV 《Journal of physiology and biochemistry》2011,67(3):415-425
Diabetes is a chronic health problem and major cause of death in most of the countries. Diet management plays an important
role in controlling diabetes and its complications along with insulin and drugs. We have examined the effect of banana (Musa sp. var. elakki bale) flower and pseudostem on hyperglycemia and advanced glycation end-products (AGEs) in streptozotocin-induced
diabetic rats. Our results indicated that banana flower and pseudostem have low glycemic index and have a high content of
dietary fiber and antioxidants. Diabetic symptoms like hyperglycemia, polyuria, polyphagia, polydipsia, urine sugar, and body
weight were ameliorated in banana flower- and pseudostem-treated rats. Increased glomerular filtration rate in the diabetic
group (5.1 ± 0.22 ml/min) was decreased in banana flower-fed (2.5 ± 0.37 ml/min) and pseudostem-fed (3.0 ± 0.45 ml/min) groups
and were significant at P < 0.001 and P < 0.01, respectively. Fructosamine and AGEs formed during diabetes were inhibited in treated groups when compared with the
diabetic group. The diabetic group showed 11.5 ± 0.64 μg of AGEs/mg protein in kidney, whereas, in banana flower- and pseudostem-fed
groups, it was reduced to 9.21 ± 0.32 and 9.29 ± 0.24 μg/mg protein, respectively, and were significant at P < 0.01. These findings suggest that banana flower and pseudostem have anti-diabetic and anti-AGEs properties and are beneficial
as food supplements for diabetics. 相似文献
6.
Barrett K McGrowder D Brown P Ragoobirsingh D 《Molecular and cellular biochemistry》2006,293(1-2):9-14
This study was designed to understand the cellular mechanisms responsible for defects in the insulin-stimulated signal transduction pathway in a type 2 diabetic animal model. We examined the in vitro PC-1 phosphodiesterase activity and glucose uptake in adipose tissue of streptozotocin (STZ)-induced type 2 diabetic rats. The PC-1 activity was significantly increased in adipose tissue of diabetic rats (0.54 ± 0.08 nmol PNTP hydrolyzed/mg protein/min) compared with controls (0.29 ± 0.05 nmol PNTP hydrolyzed/mg protein/min, p < 0.05). Upon insulin stimulation (100 nM), glucose uptake in the adipose tissue of the controls (4.17 ± 1.28×10−8 μmol/mg/min) was significantly higher than that in the diabetic rats (1.26 ± 0.35×10−8; p < 0.05). These results suggest that elevated PC-1 phosphodiesterase activity and decreased glucose uptake in adipose tissues may be acquired characteristics contributing to the development of type 2 diabetes mellitus. 相似文献
7.
Fatemi Naieni F Ebrahimi B Vakilian HR Shahmoradi Z 《Biological trace element research》2012,146(1):30-34
Premature graying of hair with unclear etiology, which is known as premature canities, is a common cause of referrals to the
dermatologists. We assessed the relationship between serum iron, copper, and zinc concentrations with premature canities.
This study was conducted on patients under 20 years old suffering from premature canities, having a minimum of ten gray hair
fibers, and referring to university hospitals of Isfahan (Iran). The results were compared with age–sex-matched controls.
Demographic data and disease characteristics were recorded for two groups. We studied serum iron, copper, and zinc concentrations
of 66 patients and 66 controls using atomic absorption and Ferrozine methods. The mean age of studied cases was 17.8 ± 2.0 years,
and the mean age of the onset of canities was 15.5 ± 3.2 years with no significant difference between males and females (P > 0.05). Serum copper concentration was significantly lower in patients compared with controls (90.7 ± 37.4 vs. 105.3 ± 50.2 μg/dL,
P = 0.048), but serum iron concentration was significantly lower in controls compared to patients (88.8 ± 39.5 vs. 108.3 ± 48.4 μg/dL,
P = 0.008). Also, there was no significant difference between patients and controls in serum zinc concentration (114.8 ± 67.8
vs. 108.2 ± 49.9 μg/dL, P = 0.285). According to these results, among copper, zinc, and iron, a low serum copper concentration may play a role in premature
graying of hairs in our society. Further studies are needed to find the underlying mechanism of this relationship. 相似文献
8.
Patients with diabetes have a much greater risk of developing heart failure than non-diabetic patients, particularly in response
to an additional hemodynamic stress such as hypertension or infarction. Previous studies have shown that increased glucose
metabolism via the hexosamine biosynthesis pathway (HBP) and associated increase in O-linked-β-N-acetylglucosamine (O-GlcNAc) levels on proteins contributed to the adverse effects of diabetes on the heart. Therefore, in this study we tested
the hypothesis that diabetes leads to impaired cardiomyocyte hypertrophic and cell signaling pathways due to increased HBP
flux and O-GlcNAc modification on proteins. Cardiomyocytes isolated from type 2 diabetic db/db mice and non-diabetic controls were treated
with 1 μM ANG angiotensin II (ANG) and 10 μM phenylephrine (PE) for 24 h. Activation of hypertrophic and cell signaling pathways
was determined by assessing protein expression levels of atrial natriuretic peptide (ANP), α-sarcomeric actin, p53, Bax and
Bcl-2 and phosphorylation of p38, ERK and Akt. ANG II and PE significantly increased levels of ANP and α-actin and phosphorylation
of p38 and ERK in the non-diabetic but not in the diabetic group; phosphorylation of Akt was unchanged irrespective of group
or treatment. Constitutive Bcl-2 levels were lower in diabetic hearts, while there was no difference in p53 and Bax. Activation
of the HBP and increased protein O-GlcNAcylation in non-diabetic cardiomyocytes exhibited a significantly decreased hypertrophic signaling response to ANG or
PE compared to control cells. Inhibition of the HBP partially restored the hypertrophic signaling response of diabetic cardiomyocytes.
These results suggest that activation of the HBP and protein O-GlcNAcylation modulates hypertrophic and cell signaling pathways in type 2 diabetes. 相似文献
9.
Ann Van Campenhout Christel M. Van Campenhout Albert R. Lagrou Begoña Manuel-y-Keenoy 《Free radical research》2013,47(10):1069-1077
Free iron is capable of stimulating the production of free radicals which cause oxidative damage such as lipid peroxidation. One of the most important mechanisms of antioxidant defense is thus the sequestration of iron in a redox-inactive form by transferrin. In diabetes mellitus, increased oxidative stress and lipid peroxidation contribute to chronic complications but it is not known if this is related to abnormalities in transferrin function. In this study we investigated the role of transferrin concentration and glycation. The antioxidant capacity of apotransferrin to inhibit lipid peroxidation by iron-binding decreased in a concentration-dependent manner from 89% at <formula>≥2 mg/ml</formula> to 42% at 0.5 mg/ml. Pre-incubation of apotransferrin with glucose for 14 days resulted in a concentration-dependent increase of glycation: 1, 5 and 13 μmol fructosamine/g transferrin at 0, 5.6 and 33.3 mmol/l glucose respectively, p<0.001. This was accompanied by a decrease in the iron-binding antioxidant capacity of apotransferrin. In contrast, transferrin glycation by up to 33.3 mmol/l glucose did not affect chemiluminescence-quenching antioxidant capacity, which is iron-independent. Colorimetric evaluation of total iron binding capacity in the presence of an excess of iron (iron/transferrin molar ratio=2.4) also decreased from 0.726 to 0.696 and 0.585 mg/g transferrin after 0, 5.6 and 33.3 mmol/l glucose, respectively, p<0.01. In conclusion, these results suggest that lower transferrin concentration and its glycation can, by enhancing the pro-oxidant effects of iron, contribute to the increased lipid peroxidation observed in diabetes. 相似文献
10.
Denisa Maceková Gustáv Ková? Jaroslav Hin?t Branislav Illek Jana Pere?ková ?elmíra Baro?ková Branislav Lí?ka 《Biologia》2010,65(1):170-174
Lipid peroxidation (LPX) can play an important role in development of functional and pathological changes of maternal tissues
in the course of pregnancy and delivery. LPX products were measured as thiobarbituric acid reacting substances (TBARS), using
malondialdehyde as the standard solution. Actual TBARS determined in maternal post-delivery plasma (2.71 ± 0.602 nmol/mL)
were not statistically different from those determined in pre-delivery plasma (3.45 ± 0.530 nmol/mL). TBARS production was
measured in vitro in the both incubated plasma (30 min, 37°C) with and without the added LPX activator (125 μM L-ascorbate plus 5 μM FeSO4). A difference in the TBARS formation was found only in the post-delivery plasma, as a result of approximately twice higher
(marginally significant) TBARS formation in the incubated plasma without the added LPX activator comparing with the actual
TBARS levels in this plasma. These results suggest that changes in maternal tissues in the process of labour could create
suitable conditions for activation of LPX in maternal plasma. On the other hand, all other analysed biochemical parameters
(iron, total iron-binding capacity, uric acid, proteins, magnesium, calcium, phosphate, glucose, potassium, sodium, chlorides,
alanine aminotransferase, aspartate aminotransferase, γ-glutamyltransferase, creatine kinase, lactate dehydrogenase, α-hydroxybutyrate dehydrogenase, α-amylase, alkaline phosphatase, acid phosphatase in the post-delivery plasma were not different from those analysed in the
pre-delivery plasma. 相似文献
11.
S. Prabodh D. S. R. S. Prakash G. Sudhakar N. V. S. Chowdary V. Desai R. Shekhar 《Biological trace element research》2011,142(1):29-35
Diabetic nephropathy is a complication of diabetes mellitus. This present study investigates the status of copper and magnesium
in diabetic nephropathy cases to establish a possible relation. Forty patients of diabetic nephropathy participated in the
study as cases. Forty age- and sex-matched healthy individuals served as controls. Blood samples were collected from both
cases and controls for determination of FBS, PPBS, HbA1c, microalbumin, copper, and magnesium levels. The mean concentrations
of FBS, PPBS, HbA1c, and microalbumin of cases were significantly higher than that of controls. The mean magnesium levels
of cases (1.60 ± 0.32 meq/L) were significantly lower than controls 2.14 ± 0.16 meq/L (p < 0.05). But the mean copper levels of cases, 165.42 ± 5.71 μg/dl, shows no significant difference with controls, 166.6 ± 5.48 μg/dl, (p > 0.05).The findings in the present study suggest that hypomagnesemia may be linked with development of diabetic nephropathy. 相似文献
12.
Intravenous (IV) iron supplementation is widely used to support erythropoeisis in hemodialysis patients. IV iron products
are associated with oxidative stress that has been measured principally by circulating biomarkers such as products of lipid
peroxidation. The pro-oxidant effects of IV iron are presumed to be due at least in part, by free or non-transferrin bound
iron (NTBI). However, the effects of IV iron on intracellular redox status and downstream effectors is not known. This prospective,
crossover study compared cytokine activation, reactive oxygen species generation and oxidative stress after single IV doses
of iron sucrose and iron dextran. This was a prospective, open-label, crossover study. Ten patients with end-stage renal disease
(ESRD) on hemodialysis and four age and sex-matched healthy were assigned to receive 100 mg of each IV iron product over 5 min
in random sequence with a 2 week washout between products. Subjects were fasted and fed a low iron diet in the General Clinical
Research Center at the University of New Mexico. Serum and plasma samples for IL-1, IL-6, TNF-α and IL-10 and NTBI were obtained
at baseline, 60 and 240 min after iron infusion. Peripheral blood mononuclear cells (PBMC) were isolated at the same time
points and stained with fluorescent probes to identify intracellular reactive oxygen species and mitochondrial membrane potential
(Δψm) by flow cytometry. Lipid peroxidation was assessed by plasma F2 isoprostane concentration. Mean ± SEM maximum serum NTBI values were significantly higher among patients receiving IS compared
to ID (2.59 ± 0.31 and 1.0 ± 0.36 μM, respectively, P = 0.005 IS vs. ID) Mean ± SEM NTBI area under the serum concentration–time curve (AUC) was 3-fold higher after IS versus
ID (202 ± 53 vs. 74 ± 23 μM*min/l, P = 0.04) in ESRD patients, indicating increased exposure to NTBI. IV iron administration was associated with increased pro-inflammatory
cytokines. Serum IL-6 concentrations increased most profoundly, with a 2.6 and 2.1 fold increase from baseline in ESRD patients
given IS and ID, respectively (P < 0.05 compared to baseline). In healthy controls, serum IL-6 was undetectable at baseline and after IV iron administration.
Most ESRD patients had increased intracellular ROS generation, however, there was no difference between ID and IS. Only one
healthy control had increased ROS generation post IV iron. All healthy controls experienced a loss of Δψm (100% with IS and
50% with ID). ESRD patients also had loss of Δψm with a nadir at 240 min. IS administration was associated with higher maximum
serum NTBI concentrations compared to ID, however, the both compounds produced similar ROS generation and cytokine activation
that was more pronounced among ESRD patients. The effect of IV iron-induced ROS production on pivotal signaling pathways needs
to be explored. 相似文献
13.
Ersoy IH Koroglu BK Varol S Ersoy S Varol E Aylak F Tamer MN 《Biological trace element research》2011,143(2):619-624
Although there are many studies on effect of fluoride on trace elements in experimental animals, few studies exist on serum
trace elements levels in patients with endemic fluorosis. We aimed to determine the serum levels of trace elements including
serum copper (Cu), zinc (Zn), and serum levels of minerals including calcium (Ca), phosphorus (P), magnesium (Mg), sodium
(Na), potassium (K) in patients with endemic fluorosis. The study group consisted of 30 patients with endemic fluorosis (17
females, 13 males, mean age 33.53 ± 9.85 years). An age, gender, and body mass index matched 30 healthy volunteers comprised
control group (21 females, ten males with a mean age 33.93 ± 7.39 years). Urine fluoride levels of chronic fluorosis patients
were significantly higher than that of control subjects as expected (1.92 ± 0.10 mg/l vs. 0.41 ± 0.09 mg/l, respectively;
P < 0.001). Serum Cu levels (89.14 ± 16.77 μg/dL vs. 102.69 ± 25.04 μg/dL, respectively, P = 0.017), serum Zn levels (77.98 ± 20.58 μg/dL vs. 94.57 ± 35.87μg/dL, respectively, P = 0.032), and serum Mg levels (1.92 ± 0.18 mg/dL vs. 2.07 ± 0.31 mg/dL, respectively, p = 0.022) was significantly lower in chronic fluorosis patients than in controls. There were no statistically significant
differences between the fluorosis group and control group with respect to serum levels of Na, K, Ca, and P. We concluded that
chronic fluorosis is associated with reduced serum levels of Cu, Zn, and Mg. 相似文献
14.
The relationship between plasma levels of homocysteine (Hcy) and femur bone mineral density (BMD) was studied in Wistar rats.
After 8 weeks of treatment with 0.5 and 1.0 g kg−1 day−1
l-methionine the mean plasma levels of Hcy were 7.67 ± 1.25 and 61.2 ± 11.4 μmol/l, respectively. Only rats treated with the
higher dose had Hcy levels significantly higher than those of controls, 6.38 ± 0.90 μmol/l (p < 0.001). Dual Energy X-ray Absorptiometry was used to measure the BMD, which was significantly lower only in the animals
with the highest plasma levels of Hcy (p < 0.001). This led us to conclude that increased levels of Hcy are associated with risk of decreased BMD. 相似文献
15.
16.
Leiter E Emri T Gyémánt G Nagy I Pócsi I Winkelmann G Pócsi I 《Folia microbiologica》2001,46(2):127-132
Late-exponential-phasePenicillium chrysogenum mycelia grown in a complex medium possessed an intracellular iron concentration of 650 μmol/L (2.2±0.6 μmol per g mycelial
dry mass). This iron reserve was sufficient to ensure growth and antibiotic production after transferring mycelia into a defined
low-iron minimal medium. Although the addition of Fe3+ to the Fe-limited cultures increased significantly the intracellular iron levels the surplus iron did not influence the production
of penicillin V. Supplements of purified majorP. chrysogenum siderophores (coprogen and ferrichrome) into the fermentation media did not affect the β-lactam production and intracellular
iron level. Neither 150 nor 300 μmol/L extracellular Fe3+ concentrations disturbed the glutathione metabolism of the fungus, and increased the oxidative stress caused by 700 mmol/L
H2O2. Nevertheless, when iron was applied in the FeII oxidation state the oxidative cell injuries caused by the peroxide were significantly enhanced. 相似文献
17.
Lucas ML Thom MM Bradley JM O'Reilly NF McIlvenny TJ Nelson YB 《The Journal of membrane biology》2005,206(1):29-42
Heat stable (STa) enterotoxin from E. coli reduced fluid absorption in vivo in the perfused jejunum of the anaesthetized rat in Krebs-phosphate buffer containing lactate
and glucose (nutrient buffer), in glucose saline and in glucose free saline. Bicarbonate ion enhanced fluid absorption of
98 ± 7 (6) μl/cm/h was very significantly (P < 0.0001) reduced by STa to 19 ± 4 (6) μl/cm/h, but net secretion was not found. When impermeant MES substituted for bicarbonate
ion, net fluid absorption of 29 ± 3 (6) μl/cm/h was less (P < 0.01) than the values for phosphate buffer and bicarbonate buffer. With STa in MES buffer, fluid absorption of 3 ± 2 (6)
μl/cm/h was less than (P < 0.001) that in the absence of STa and not significantly different from zero net fluid absorption. E. coli STa did not cause net fluid secretion in vivo under any of the above circumstances. Neither bumetanide nor NPPB when co-perfused
with STa restored the rate of fluid absorption. In experiments with zero sodium ion-containing perfusates, STa further reduced
fluid absorption modestly by 20 μl/cm/h. Perfusion of ethyl-isopropyl-amiloride (EIPA) with STa in zero sodium ion buffers
prevented the small increment in fluid entry into the lumen caused by STa, indicating that the STa effect was attributable
to residual sodium ion and fluid uptake that zero sodium-ion perfusates did not eradicate. These experiments, using a technique
that directly measures mass transport of fluid into and out of the in vivo proximal jejunum, do not support the concept that
E. coli STa acts by stimulating a secretory response. 相似文献
18.
Kedzierska K Bober J Ciechanowski K Gołembiewska E Kwiatkowska E Noceń I Dołegowska B Dutkiewicz G Chlubek D 《Biological trace element research》2005,107(1):21-32
The aim of the study was to verify the hypothesis if copper could influence the activity of sodium-transporting systems in
erythrocyte membrane that could be related to essential hypertension. The examined group of patients consisted of 15 men with
hypertension. The control group was 11 healthy male volunteers. The Na+/H+ exchanger (NHE) activity in erythrocytes was determined according to Orlov et al. The activity of transporting systems (ATP-Na+/K+; co-Na+/K+/Cl−; ex-Na+/Li+; free Na+ and K+ outflow [Na+, K+-outflow]) was determined according to Garay's method. The concentration of copper in plasma was assessed using atomic absorption
spectrometry. The activity of ATP-Na+/K+ (μmol/L red blood cells [RBCs]/h) in hypertensive patients was 2231.5±657.6 vs 1750.5±291 in the control (p<0.05), the activity of co-Na+/K+/Cl− (μmol/L RBCs/h) in hypertensives was 171.3±77.9 vs 150.7±53.9 in the control (NS). Na+-outflow (μmol/L RBCs/h) in hypertensives was 118.3±51.6 vs 113.3±24.4 in the control (NS). The K+-outflow (μmol/L RBCs/h) in hypertensives was 1361.7±545.4 vs 1035.6±188.3 in the control (NS). The activity of ex-Na+/Li+ (μmol/L RBCs/h) in hypertensive patients was 266.1±76.1 vs 204.1±71.6 in the control (p<0.05). NHE activity (mmol/L RBCs/h) in hypertensives was 9.7±2.96 vs 7.7±1.33 in the control (p<0.05). In hypertensive patients, negative correlation was found between the activity of Na+/K+/Cl− co-transport and plasma copper concentration (R
s=−0.579, p <0.05) and between the activity of ex-Na+/Li+ and plasma copper concentration (R
s=−0.508, p<0.05). Plasma copper concentration significantly influences the activity of sodium transporting systems in erythrocyte membrane.
Copper supplementation could be expected to provide therapeutic benefits for hypertensive patients. 相似文献
19.
Hydrogen peroxide plays a major role in the pathomechanism of diabetes mellitus and its main regulator is enzyme catalase.The blood catalase and the C111T polymorphism in exon 9 was examined in type 1, type 2 and gestational diabetes mellitus.Compared to the control group (104.7 ± 18.5 MU/l) significantly decreased (p < 0.001) blood catalase activities were detected in type 2 (71.2 ± 14.6 MU/l), gestational (68.5 ± 12.2 MU/l) diabetes mellitus and without change in type 1 (102.5 ± 26.9 MU/l). The blood catalase decreased (p = 0.043) with age for type 2 diabetics and did not change (p>0.063) for type 1, gestational diabetic patients and controls. Blood catalase showed a weak association with hemoglobin A1c for type 1 diabetic patients (r = 0.181, increasing).The mutant T allele was increased in type 1 and gestational diabetes mellitus, and CT+TT genotypes showed decreased blood catalase activity for type 1 and increased activities for type 2 diabetic patients.The C111T polymorphism may implicate a very weak effect on blood catalase activity in different types of diabetes mellitus. 相似文献
20.
Metabolic hotspots at land–water interfaces are important in supporting biogeochemical processes. Here we confirm the generality
of land–aquatic interfaces as biogeochemical hot spots by extending this concept to marine beach cast materials. In situ atmospheric
pCO2, from a respiration chamber (10 cm in diameter and 20 cm high) inserted into wrack deposits, was determined using a high-precision
(±1 ppm) non-dispersive infrared gas analyzer (EGM-4, PP-systems) at 1 minute recording intervals. The wrack deposits supported
high metabolic activities, with CO2 fluxes averaging (±SE) 6.62 ± 0.88 μmol C m−2 s−1, compared to median value of 0.98 μmol C m−2 s−1 (mean 2.21 ± 1.25 μmol C m−2 s−1) for bare sand adjacent to deposits. Wrack metabolic rates ranged 40-fold across beaches, from a minimum of 0.57 ± 0.22 μmol
C m−2 s−1 to a maximum of 20.8 ± 5.04 μmol C m−2 s−1, both derived from beaches with deposits dominated by Sargassum. Rates tended to increase significantly (F test, P < 0.05) from the shoreline to reach maximum rates at about 10 m from the shoreline, declining sharply further from the shoreline,
and increased with increasing thickness of the deposits (maximum about 10 cm deep), declining for thicker deposits. Wrack
differing in composition had similar metabolic rates, although deposits consisting of a mixture of seagrass and algae tended
to show somewhat higher rates. Our results show a meter square of wrack deposit supports a metabolic rate equivalent to that
supported by 3 m2 of living seagrass or macroalgal habitat. In wrack, the marine environment provides organic material and moisture and the
land environment provides oxygen to render wrack ecosystems an efficient metabolic reactor. Intense wrack metabolism should
also be conducive to organismal growth by supporting the development of a cryptic, but diverse wrack-based food web. 相似文献