Effect of acute swimming exercise on lactate levels and its relation with zinc in pinealectomized rats

It is argued that melatonin secreted from the pineal gland regulates the levels of zinc, which is an important trace element. Decreases in zinc levels of pinealectomized rats supports this relationship. There is an increasing amount of evidence suggesting that the pineal gland can have important effects on physical activity. The objective of the present study was to explore the changes in serum lactate levels in pinealectomized rats subjected to acute swimming exercise and its relation with zinc. Forty adult male rats of Spraque Dawley strain were equally allocated to four groups. Group 1: General Control Group. Group 2: Pinealectomized Control Group. Group 3: Swimming Control Group. Group 4: Pinealectomized Swimming Group. Serum zinc, melatonin and lactate levels were determined in the blood samples collected from the animals by a decapitation method. Zinc and melatonin levels were higher in Group 1 than in Groups 2, 3 and 4 (p < 0.01), higher in Group 3 than in Groups 2 and 4 (p < 0.01) and higher in Group 2 than in Group 4 (p < 0.01). The highest lactate levels were found in Group 4 (p < 0.01). Lactate levels in Group 3 were higher than those in Groups 1 and 2 (p < 0.01), while the levels in Groups 1 and 2 did not differ. Pinealectomy results in a significant increase in lactate levels in rats subjected to an acute swimming exercise. This increase in lactate levels may be associated with the decrease observed in zinc levels after pinealectomy.     

Cardiac copper,magnesium, and zinc in recent and old myocardial infarction

X-ray fluorescence spectrometry and atomic absorption spectrometry were used in a quantitative study of zinc, copper, and magnesium in 71 postmortal human hearts. Samples were obtained from individuals who had demonstrated no previous clinical or subsequent pathological findings of myocardial infarction and from victims of a recent or an old infarction. A significant difference (p<0.001) in the elemental levels was observed between the noninfarct and the recent infarct groups. The noninfarct group had higher cardiac levels of all three elements. However, the difference in elemental concentrations between the noninfarct and the old-infarct groups was not significant. Cardiac levels of zinc (p<0.001) and copper (p<0.01) were significantly greater in the old-infarct group than in the recent-infarct group. Magnesium levels were higher in the recent-and-old-infarct group than in the recent infarct group (p<0.01). It is possible that the elements are redistributed during myocardial infarction, and that uptake of these elements (from the serum pool) by the heart may be important in maintaining myocardial integrity and function.     

Changes in iron, calcium, magnesium, copper, and zinc levels in different tissues of riboflavin-deficient rats

To clarify the changes of mineral levels in different tissues of riboflavin-deficient rats, Wistar rats were separated into three groups. One group was fed a diet ad libitum that was deficient in riboflavin. The other two were fed either the complete diet that was weight-matched to the riboflavin-deficient group or fed a complete diet ad libitum. In riboflavin-deficient rats, the hemoglobin concentration and riboflavin contents of blood, liver, and kidney were significantly decreased, compared with weight-matched and ad libitum-fed controls. The mineral concentrations of tissues are summarized as follows: The iron (Fe) concentration in the heart, liver, and spleen was decreased in the riboflavin-deficient group compared with the other groups. Calcium (Ca) and magnesium (Mg) concentrations in tibia were decreased in the riboflavin-deficient group compared with the other two groups. Copper (Cu) concentration was increased in the heart and liver when the riboflavin-deficient group was compared with the other groups. Zinc (Zn) concentration was increased in tibia when the riboflavin-deficient group was compared with the other groups.     

长期游泳运动对大鼠铁状态的影响

目的：观察不同的运动时间对铁状态的影响。方法：大鼠随机分为3、6、12个月的三个游泳运动组和相应安静组;运动期满后观察血液学铁状态指标和器官非血红素铁(NHI)含量和NHI总含量(TNHI)的变化。结果：与安静组相比,三种不同时间长度的运动均诱导一种具有血浆铁浓度降低、血浆转铁蛋白铁饱和度降低而血红蛋白浓度和红细胞比容得到雏持的血液学低铁状态;这种低铁状态伴有肝、脾、心、肾NHI浓度显著降低,但与运动时间无关;肝、脾和肾TNHI变化与其浓度变化方向一致,但心脏没有显著变化;上述器官TNHI随时间增加而增多。结论：尽管运动诱导的低铁状态类似于铁缺乏中期表现,但由于器官NHI重分布和铁贮存并没有进行性降低,因此,长期运动引起的低铁状态可能是机体内铁代谢对运动的适应,不存在所谓“运动性铁缺乏”现象。     

Serum magnesium, copper, and zinc alterations following spinal fusion

Changes in serum magnesium, copper and zinc values were evaluated in spinal fusion patients at four monitorings. For magnesium and copper individually, a significant difference was found between the mean values at each monitoring (p<0.05), whereas the changes of zinc values between four monitorings were insignificant. There was no statistical difference between the changes of each trace element values and gender, age, operative time, intraoperative blood loss, blood replacement, number of the vertebral levels fused, and antibiotic type used. As a result, magnesium can be suggested to be more important than the other two elements in the postoperative period. Alterations of serum magnesium, copper, and zinc values do not have any correlation with the fusion of the spinal column, either with the width of the fused area or operative time and blood loss. This study cannot confirm the exact reason for this entity and the etiology remains speculative. There is no need for magnesium, copper, or zinc supplementation during the surgical period for the patients. It will be worthy to evaluate the patients who were sent to the intensive care unit after spinal surgery and compare their results with the other intensive care patients.     

Regional distribution of metallothionein, zinc, and copper in the brain of different strains of rats

The regional brain distribution of metallothionein (MT), zinc, and copper in the brain was determined in nine anatomical regions (olfactory bulb, cortex, corpus striatum, hippocampus, thalamus plus hypothalamus, pons plus medulla oblongata, cerebellum, midbrain, and white matter) and was compared between two different strains of rat (Sprague-Dawley [SD] and Lewis). No significant difference was observed in the whole-brain MT level between the two strains (17.8 ± 3.4 μg/g in SD rats and 20.3 ± 2.3 μg/g in Lewis rats). In SD rats, however, MT was more highly expressed in the white matter than in the other regions studied. In contrast, MT concentration was highest in the cortex and lowest in the olfactory bulb in Lewis rats. The MT levels in the cortex, corpus striatum, hippocampus, and thalamus plus hypothalamus were significantly lower in SD rats than in Lewis rats. In both strains, the olfactory bulb contained markedly higher levels of both zinc and copper than the other regions (27.9 ±6.8 μg/g zinc in SD rats and 27.6 ± 6.9 μg/g zinc in Lewis rats, and 5.2 ± 1.5 μg/g copper in SD rats and 11.1 ± 4.8 μg/g copper in Lewis rats). The next high-est zinc levels were seen in the hippocampus, whereas the next highest copper levels were in the corpus striatum in both SD and Lewis rats. The high levels of zinc and copper in the olfactory bulb were not accompanied by concomitant high MT concentrations. These results indicate that the strain of rat as well as the anatomical brain region should be taken into account in MT and metal distribution studies. However, the highest concentrations of zinc and copper in olfactory bulb were common to both SD and Lewis rats. The discrepancy between MT and the metal levels in olfactory bulb suggests a role for other proteins in addition to MT in the homeostatic control of zinc and copper.     

Effects of iron,copper, zinc,calcium, and magnesium on human lymphocytes in culture

The effects of simultaneous changes of calcium, magnesium, iron, copper, and zinc concentrations were evaluated in normal human T and B lymphocytes, cultured in cation-depleted media. Optimal concentrations for thymidine incorporation (TI) in both cell populations were Fe and Zn 15 μM and Cu 5 μM; for t cells Ca 2 mM and Mg 4 mM; for B cells Ca 4 mM and Mg 6 mM. TI decreased with increasing molarity of cations and the decrease was particularly apparent with Cu. Minimal amounts of Ca and Mg (0.5 mM) were necessary for growth, even in presence of optimal concentrations of Fe, Cu, and Zn. Fe and Cu showed synergistic stimulatory effects at low concentrations and synergistic inhibitory effects at high concentrations. Antagonism between Fe and Zn, Cu and Zn, and Ca and Zn was also demonstrated. CD4/CD8 increased with PHA stimulation in presence of Zn, and decreased with ConA stimulation in presence of Zn or Fe. The results demonstrate: (1) the relationship and interdependence of Fe, Cu, and Zn concentrations in modulating the growth of normal lymphocytes; (2) the stimulatory effects of Fe on B cells and Zn on CD8 positive cells; (3) the inhibitory effect of Cu at concentrations lower than those of Fe and Zn; (4) the requirement of Ca and Mg in certain concentration and ratio for the action of the other cations; and (5) the Ca and Mg requirement for the growth of B cells higher than T cells.     

Tissue and blood levels of zinc, copper, and magnesium in nitric oxide synthase blockade-induced hypertension

The aim of this study was to determine the levels of tissue and blood zinc (Zn), copper (Cu), magnesium (Mg) in nitric oxide (NO) synthase blockade-induced hypertension. A group of albino rats received a NO synthase inhibitor, N ^G -nitro-l-arginine-methyl ester (l-NAME, 60 mg/kg/d) in their drinking water for 21 d. l-NAME intake caused a progressive rise in this group’s resting mean arterial blood pressure compared to a control group (p<0.01). There were no differences between the groups with regard to tissue and blood levels of Zn or Cu; however, Mg concentrations were significantly lower in the hypertensive rats’ erythrocytes (20.2% reduction from control levels), cerebral cortex (17.0%), heart (9.1%), renal cortex (12%), renal medulla (16.7%), and in the tissues of the caval vein (23.7%), mesenteric artery (29.8%), renal artery (18.4%), and renal vein (22.1%). There were no significant Mg concentration changes in the hypertensive group’s plasma, cerebellum, liver, duodenum, or aortal tissue. These findings suggest that Mg depletion may play a role in the blood pressure rise that occurs in the model of chronic NO synthase inhibition-induced hypertension.     

Selenium status,plasma zinc,copper, and magnesium in vegetarians

Plasma zinc (Zn), copper (Cu), and magnesium (Mg) concentrations, copper/zinc ratio, and selenium (Se) status were studied in 44 vegetarians (22 males and 22 females) and their age- and sex-matched nonvegetarians in the Bratislava region (Slovakia). Vegetarians had statistically significant lower levels of plasma Zn and Cu than nonvegetarians, which may be the result of lower bioavailability of Zn and Cu from this type of diet. No differences in plasma Mg levels were found between vegetarians and nonvegetarians. Se status, as expressed by plasma and erythrocyte concentrations and plasma and erythrocyte glutathione peroxidase activities (GPx), was significantly lower in vegetarians when compared to nonvegetarians. In the series as a whole, there were significantly higher correlations between plasma and erythrocyte Se concentrations and between plasma and erythrocyte GPx activities. Significant positive correlations were also found between plasma Se concentrations and erythrocyte GPx activities, and between erythrocyte Se concentrations and erythrocyte GPx activities. A vegetarian diet does not provide a sufficient supply of essential antioxidant trace elements, like Zn, Cu, and especially Se. Se supplementation should be recommended to this risk group of the population.     

运动对老年肥胖大鼠脂联素的影响

目的：探讨运动对老年肥胖大鼠内脏脂肪组织脂联素mRNA和蛋白质表达、血浆脂联素浓度及胰岛素抵抗的影响。方法：取雄性SD大鼠,鼠龄21 d,分青春期、壮年期和老年期三个阶段喂养高脂饲料（脂肪率为36.3%~40.0%）,建立老年肥胖模型。鼠龄达到60周后,取自然生长老年大鼠随机分为对照组（C）和老年运动组（AE）,n=6;取老年肥胖大鼠随机分为肥胖对照组（OC）和肥胖运动组（OE）,n=6。动物跑台坡度0°,运动速度及时间为（15 m/min×15 min）,4组/次,组间休息5 min,每次共运动60 min,5次/周,持续运动8周。8周后,检测内脏脂肪组织脂联素mRNA和蛋白质表达,测定血糖、血浆脂联素浓度和胰岛素浓度,计算胰岛素抵抗。结果：运动干预后,与对照组比较,肥胖对照组大鼠脂联素mRNA和蛋白质表达显著减低,血糖浓度和胰岛素抵抗明显增高;而老年运动组大鼠脂联素mRNA和蛋白质表达显著增高。与肥胖对照组大鼠比较,肥胖运动组大鼠脂联素mRNA和蛋白质表达显著增高、血浆脂联素水平增高,血糖浓度和胰岛素抵抗明显减低。结论：老年肥胖大鼠内脏脂肪组织脂联素mRNA和蛋白质表达均降低,伴随胰岛素抵抗、血糖升高。运动能显著增加其内脏脂肪组织脂联素mRNA和蛋白质表达,升高血浆脂联素水平,改善胰岛素抵抗,降低血糖。     

Dietary zinc effects on zinc, calcium, and magnesium content in bones of growing rats

The aim of the present study was to assess dietary zinc effects on femur weight and mineral content in growing rats. For this purpose, 70 weanling Sprague-Dawley rats were divided into four groups. Each group was subject to a diet containing 2 (BZ), 5 (DZ), 10 (MZ), and 30 (CZ) ppm zinc. The calcium and magnesium content in all diets was 5 g/kg and 507 mg/kg, respectively. The animals were kept on this regime for 28 d and then sacrificed and their femurs were removed for analysis using atomic absorption spectrophotometry. The weights of the BZ and DZ groups were significantly different from the MZ and CZ groups (38.5±10.5, 89.9±13.7, 118.6±13.6 and 134±19.9 g, p<0.01) respectively. There were no differences between the MZ and CZ groups. Femur weight also varied with dietary zinc, as it was significantly different among all groups (BZ, 265±49 mg; DZ, 380±40 mg; MZ, 452±54 mg; CZ, 735±66 mg; p<0.01). The femur zinc content varied with diets, following a different pattern than the above parameters. Femur zinc from the BZ group (51.5±5.4 ppm) was significantly different from the MZ and CZ groups (115.9±14.2 and 175.0±13.5 ppm, respectively), whereas the DZ group (62.5±11.3 ppm) did not differ from the other three groups. The femur content of calcium (BZ, 83.2±9.8 mg/g; DZ, 88.0±9.2 mg/g; MZ, 90.2±13.6 mg/g; CZ, 83.1±14.7 mg/g) and magnesium (BZ, 1.82±0.13 mg/g; DZ, 1.98±0.09 mg/g; MZ, 1.93±14 mg/g; CZ, 1.83±0.19 mg/g) were not significantly different among the groups, nor was the calcium-magnesium ratio. These results suggest that although dietary zinc deficiency retards growth and causes bone fragility, bone deposition of calcium and magnesium and its ratio are not affected.     

Lead, copper, zinc, and magnesium content in hair of children and young people with some neurological diseases

The lead, copper, zinc, and magnesium levels of scalp hair taken from 153 children aged 1–15 yr and young people (16–18 yr) with selected neurological disorders (hyperexcibility, loss of consciousness, and epileptiform convulsions of an unknown origin, etc.), were measured using the atomic absorption spectrometry method and then compared with a control group of healthy children (n=108). The research indicated significantly reduced mean levels of magnesium in the hair of children suffering from selected neurological diseases (in children aged 11–15 yr of age, above 30%; up to 5 yr of age, nearly 30%; the differences were statistically significant at p<0.05) and slightly decreased mean levels of copper (differences statistically significant at p<0.05, particularly in the 11 to 15-yr category). Differences in zinc levels in hair were inconsiderable (not statistically significant in any age groups). The lead level in the hair of the above-mentioned group of children was exceeded in relation to the control group (a statistically significant difference at p<0.05 for the total group). A more than twofold decrease in the mean value of the Mg/Pb ratio (and a nearly 30% decrease in the value of the Mg/Zn ratio) in the hair of children suffering from neurological diseases suggests that the high toxicity of lead accompanying, among other things, magnesium deficiencies might be a cause of the observed disorders in children.     

Effects of oral zinc and magnesium supplementation on serum thyroid hormone and lipid levels in experimentally induced diabetic rats

This study was designed to investigate the effects of oral zinc and magnesium supplementation on serum thyroid hormone and lipid levels in alloxan-induced diabetic rats. Thirty-two albino male rats, weighing 234±34 g, were divided into four experimental groups (control, diabetic, diabetic+zinc supplemented and diabetic+ magnesium supplemented). The experiment lasted for 60 d. The first 45 d of the experiment was the supplementation and last 15 d was the supplementation and diabetes-inducing period. Diabetic+zinc-supplemented and diabetic+magnesium-supplemented groups were given orally (by adding in their drinking water) 227 mg/L of zinc and 100 mg/kg body weight (bw) of magnesium, respectively throughout the experiment. Control and diabetic groups served as controls and did not receive zinc or magnesium supplementation. Diabetic, diabetic+zinc-supplemented, and diabetic+magnesium-supplemented groups were given a daily injection (ip) of 100 mg/kg bw of alloxan for 15 d starting on d 46 of the experiment. The control group was only injected with the same volume of isotonic NaCl as the diabetic group received. At the end of the of the experiment, rats in all four groups were fasted for 12 h and blood samples were taken from the heart under ether anesthesia for the determination of thyroid hormone, glucose, total cholesterol, and triglyceride concentrations. It was found that serum glucose, total cholesterol, and triglyceride concentrations were higher and serum T3 and T4 concentrations were lower in diabetic rats than those in the control group. Zinc supplementation did not change any parameter in diabetic rats. However, magnesium supplementation decreased the elevated total cholesterol and triglyceride concentrations of the diabetic rats to the control level. It was concluded that oral magnesium supplementation might decrease the diabetes-induced disturbances of lipid metabolism.     

Effects of zinc deficiency and supplementation on malondialdehyde and glutathione levels in blood and tissues of rats performing swimming exercise

The aim of the study was to investigate the effects of zinc deficiency and supplementation on lipid peroxidation and glutathione levels in blood and in some tissues of rats performing swimming exercise. Forty adult male Sprague-Dawley rats were divided into four groups: group 1, zinc-deficient consisted of swimming rats; group 2 consisted of zinc-supplemented swimming rats; groups 3 and 4 were the swimming and nonswimming controls, respectively. The levels of malondialdehyde and glutathione were measured after 4 wk of zinc-deficient or zinc-supplemented diet and 30 min of swimming exercise daily. The erythrocyte glutathione levels of groups 2 and 4 were significantly higher than those of groups 1 and 3 (p<0.01). The plasma malondialdehyde level of group 1 was significantly higher than all other groups. The glutathione levels in liver, kidney, striated muscle, and testes of group 2 were higher than in the other groups (p<0.01) and higher in kidney and striated muscle of group 3 than in groups 1 and 4 (p<0.01). The tissue malondialdehyde levels of striated muscle, liver, kidney, and testes of group 1 were significantly higher than for all other groups (p<0.01). Our findings suggest that both swimming exercise and zinc deficiency result in an increase of lipid peroxidation in tissues and that zinc supplementation prevents these alterations by the activation of the antioxidant system.     

Concentations of copper, Zinc, and magnesium in sera from patients with idiopathic dilated cardiomyopathy

Trace elements are known to have a key role in myocardial metabolism. The accumulation (cobalt, arsenic, copper) or deficiency (selenium, zinc) of trace elements may be responsible for idiopathic dilated cardiomyopathy. We investigated the trace element concentrations (Cu, Zn, Mg) in sera from patients with dilated cardiomyopathy by atomic absorption spectrophotometry. We observed that patients with dilated cardiomyopathies have higher copper and lower zinc concentrations in serum than healthy controls. The magnesium concentrations of patients did not differ significantly from that of control subjects.     

Calcium, magnesium, and zinc status in experimental hypothyroidism

In this study, experimental hypothyroidism was established and used to investigate possible alterations in the calcium, magnesium, and zinc homeostasis by assessing their concentration in plasma and erythrocytes. Hypothyroidism was induced by administration of methimazole an iodine blocker at a dose of 75 mg/100 g food for 3 wk. In the methimazole-induced hypothyroid state, the experimental animals showed a significant decrease in plasma zinc concentration, whereas a significant increase in plasma magnesium concentration occurred. No change was observed in plasma calcium concentration. The erythrocyte zinc and calcium concentrations were found to be increased, whereas magnesium concentration decreased. Erythrocyte magnesium concentration showed a significant positive correlation with T₄ values. The study provides evidence for marked alterations in homeostatis of zinc, magnesium, and calcium.     

Effect of supplemental magnesium on the kidney levels of cadmium, zinc, and copper of mice exposed to toxic levels of cadmium

In this report, we present the results of our investigations on the effect of Mg pretreatment on Cd and bioelements (Cu and Zn) contents in kidney of mice exposed to acute and subacute Cd intoxication. Acute intoxication was performed on male Swiss mice given a single oral dose of 20 mg Cd/kg body weight and mice given the same dose of Cd but pretreated with 40 mg Mg/kg body weight. For subacute intoxication one group of mice was given 10 mg Cd/kg body weight every day, for 2 wk, and the other one received the same dose of Cd after oral Mg intake of 20 mg/kg body weight. Cd, Cu, and Zn content was determined in kidney by atomic absorption spectrophotometry. In acute Cd intoxication, Mg pretreatment resulted in significant decrease of Cd in kidney after 4 and 6 h, compared with animals given only Cd. Under the condition of subacute Cd intoxication, Mg supplementation reduced Cd kidney content after 2 wk for about 30%, compared with animals treated with Cd only. The effect of Mg on Cu and Zn kidney content was also beneficial.     

Effect of medium copper concentration on the growth,uptake and intracellular balance of copper and zinc in Menkes' and normal control cells

The precise nature of the variation in cellular copper load against medium copper concentration is defined using a comprehensive logarithmically incremented series of medium copper concentrations ranging from low levels (4.8 p.p.b.) through normal to toxic levels (40 p.p.m.) in which fibroblasts were grown followed by determination of intracellular content. Menkes' fibroblasts showed an unexpected plateau region of stable intracellular copper content against a change in medium concentration of over 100-fold, albeit only when sufficient copper was present in the medium (0.08–8.0 p.p.m.). Thus, Menkes' cells are clearly capable of balancing uptake/efflux providing copper availability allows. Simultaneous analysis of cellular copper and zinc load at various medium copper concentrations shows an indistinguishable intracellular copper:zinc ratio between the two cell lines. The nature of non-labeled copper uptake by fibroblasts over a 40 min and 7 day period is reported. During the 40 min period copper uptake (20 p.p.m.) was essentially the same in both cell lines. However, copper absorbed was superimposed upon large pre-existing copper pools in the case of Menkes' cells only. Advantages of techniques determining non-labeled copper in copper uptake/efflux experiments are discussed in the light of these results. Fibroblast growth studies showed that, compared with normal cells, Menkes' cells are significantly (P < 0.01) more growth sensitive to extended exposure to low copper concentrations. Thus, Menkes' disease appears to be not only a result of copper maldistribution but also a direct result of an inability of Menkes' cells to function normally in low copper environments.     

短期和长期运动预适应对力竭大鼠心肌损伤的保护作用

目的：研究短期和长期运动预适应对心肌细胞凋亡保护中发挥的作用及机制。方法：48只雄性SD大鼠随机分为对照组（C）、力竭组（E）、短期运动预适应组（S-EP）、长期运动预适应组（L-EP）。短期和长期运动预适应分别进行3 d和3周的反复间歇游泳训练方案。光镜下观察心肌细胞的结构改变;ELISA方法检测血清中缺血修饰白蛋白（IMA）、磷酸肌酸同工酶（CK-MB）含量;实时荧光定量PCR和Western blot方法检测心肌组织中TNF-α、Caspase-8、Caspase-3基因和蛋白表达;采用DNA原位末端标记（TUNEL）法观察心肌细胞的凋亡情况。结果：与C组相比,E组心肌细胞损伤严重,血清IMA、CK-MB含量及心肌组织中TNF-α、Caspase-8、Caspase-3 mRNA和蛋白表达升高（P<0.05）;与E组相比,S-EP组血清CK-MB及心肌TNF-α、Caspase-8mRNA明显降低（P<0.05）,而蛋白表达无统计学差异,血清IMA及Caspase-3 mRNA和蛋白均下降不明显,无统计学意义（P>0.05）,L-EP组血清IMA、CK-MB含量及心肌TNF-α、Caspase-8、Caspase-3 mRNA及蛋白明显降低,有统计学意义（P<0.05）;与S-EP组相比,L-EP组血清IMA、CK-MB含量及TNF-α、Caspase-8、Caspase-3 mRNA和蛋白明显下降,有统计学意义（P<0.05）。E组心肌细胞凋亡明显,S-EP组和L-EP组均能抑制凋亡,且L-EP组与S-EP组相比心肌凋亡明显减少。结论：短期和长期运动预适应均可减轻力竭后的心肌损伤,但短期运动预适应并未改变Caspase蛋白酶的表达,长期运动预适应明显抑制Caspase-8、3 mRNA表达,减少蛋白合成,从而发挥心肌保护效应,故长期运动预适应在抑制心肌细胞凋亡方面较短期运动预适应更强。     

Acute supplementation of valine reduces fatigue during swimming exercise in rats

We investigated the respective effects of the acute supplementation of valine, leucine, and isoleucine on metabolism-related markers by administering a swimming exercise test to rats. As a behavioral analysis, we evaluated the effect of valine and that of leucine on spontaneous activity after exercise. Acute supplementation of valine before exercise significantly suppressed the depression of the liver glycogen and the blood glucose after exercise, whereas leucine decreased the blood glucose and isoleucine had no effect. Valine or leucine supplementation significantly decreased the plasma corticosterone level after exercise, while isoleucine had no effect. In the behavioral analysis, valine significantly increased the spontaneous activity after exercise, whereas leucine had no effect. These results indicate that in rats, the acute supplementation of valine, not leucine or isoleucine, is effective for maintaining liver glycogen and blood glucose and increasing spontaneous activity after exercise, which could contribute to the reduction of fatigue during exercise.