Melatonin has a protective effect against lipid peroxidation in the bone tissue of diabetic rats subjected to acute swimming exercise.

Aim The present study aimed to examine the effects of melatonin supplementation on lipid peroxidation in the bone tissue of diabetic rats subjected to acute swimming exercise. Methods The study was conducted on 80 Sprague-Dawley type adult male rats which were equally allocated to eight groups: group 1, general control; group 2, melatonin-supplemented control; group 3, melatonin-supplemented diabetic control; group 4, swimming control; group 5, melatonin-supplemented swimming; group 6, melatonin-supplemented diabetic swimming; group 7, diabetic swimming; group 8, diabetic control. In order to induce diabetes, the animals were subcutaneously injected with 40 mg/kg streptozotocin (STZ). The animals were supplemented with 3 mg/kg/day melatonin intraperitoneally (IP) for 4 weeks. At the end of the study, the animals were decapitated to collect bone tissue samples which were examined to find out the malondialdehyde (MDA) (nmol/g/protein) and glutathione (GSH) (mg/dL/g protein) levels. Results The highest MDA values in the bone tissue were found in groups 7 and 8. MDA levels in the bone tissue in groups 3 and 6 were lower than the levels in groups 7 and 8, but higher than those in all other groups. Groups 3, 5 and 6 had the highest bone tissue GSH values. On the other hand, the lowest GSH level was established in groups 7 and 8. Conclusion The results of the present study indicated that the cell damage caused by acute swimming exercise and diabetes in the bone tissue could be prevented by melatonin supplementation.

Review - Selenium - Its metabolism and relation to exercise.

Selenium (Se), which is commonly found in nature, is one of the essential trace elements necessary for the normal development of human and animal organisms. Selenium was first defined in 1818 by the Swedish chemist Berzelius in sulfuric acid residues. At the end of 1960s, the role of selenium in human health began to attract attention and human diseases that resembled animal diseases responding to selenium was started to be investigated. Selenium, which is highly important for human health, is necessary for a variety of metabolic processes, including thyroid hormone metabolism, protection against oxidative stress and immunity functions. Selenium is a molecule that activates glutathione peroxidase, and thus, it is involved in the antioxidant mechanisms that prevent oxidant damage. Exhaustive physical exercise is known to cause oxidant damage, probably by promoting free radical production in many tissues, including muscle, liver, heart and lungs in animals. The increase in oxidative stress during exercise and recognition of selenium's stimulation of antioxidant activity inevitably suggest a relation between selenium and exercise. The present review aims to provide information on selenium metabolism and the relation between selenium and exercise.

Effects of zinc supplementation on the element distribution in kidney tissue of diabetic rats subjected to acute swimming.

In this study, we report the effect of zinc supplementation on the distribution of elements in kidney tissue of diabetic rats subjected to acute swimming exercise. Diabetes was induced by two subcutaneous injections of 40 mg/kg of streptozotocin within a 24-h period. Zinc was given intraperitoneally at a dose of 6 mg/kg per day for a period of 4 weeks. The rats (n = 80) were equally divided into eight study groups: controls, zinc-supplemented, swimming, diabetic, zinc-supplemented diabetic, zinc-supplemented swimming, diabetic swimming, and zinc-supplemented diabetic swimming. The levels of lead, cobalt, molybdenum, chromium, boron, magnesium, iron, copper, calcium, zinc, and selenium were determined in the kidney tissue samples by ICP-AES. Higher molybdenum, calcium, zinc, and selenium values were found in both swimming and nonswimming diabetic rats. Significantly higher iron values were found in swimming, diabetic, diabetic swimming, and zinc-supplemented diabetic swimming rats (p < 0.001). Diabetic, zinc-supplemented diabetic, diabetic swimming, and zinc-supplemented diabetic swimming rats had the highest copper values. These results show that zinc supplementation normalized the higher levels of molybdenum, calcium, selenium, and iron levels seen in diabetic rats, indicating that zinc may have a regulatory effect on element metabolism in kidney tissue.

Effect of zinc supplementation on the distribution of various elements in the serum of diabetic rats subjected to an acute swimming exercise

No disponible

The present study aims to examine the effect of supplementation of zinc on the distribution of various elements in the sera of diabetic rats subjected to an acute swimming exercise. A total of 80 Sprague–Dawley-type adult male rats were equally allocated to one of eight groups: Group 1, general; Group 2, zinc-supplemented; Group 3, zinc-supplemented diabetic; Group 4, swimming control; Group 5, zinc-supplemented swimming; Group 6, zinc-supplemented diabetic swimming; Group 7, diabetic swimming; and Group 8, diabetes. The rats were injected with 40 mg/kg/day subcutaneous streptozotocin (STZ) twice, with a 24-h interval between two injections. Zinc was supplemented at a dose of 6 mg/kg/day (ip) for 4 weeks. Blood samples were collected at the end of the 4-week study, and serum levels of lead, cobalt, molybdenum, chrome, sulfur, magnesium, manganese, sodium, potassium, phosphorus, copper, iron, calcium, zinc, and selenium (mg/L) were determined with atomic emission. The lowest molybdenum, chrome, copper, iron, potassium, magnesium, sodium, phosphorus, lead, selenium, and zinc values were obtained in Group 7 and 8. These same parameters were higher in the swimming exercise group (Group 4), relative to all other groups. The values in zinc-supplemented groups were found lower than the values in Group 4, but higher than those in Group 6 and 7. The results obtained from the study demonstrate that acute swimming exercise and diabetes affect the distribution of various elements in the serum, while zinc supplementation can prevent the negative conditions associated with both exercise and diabetes (AU)

Interactive effects of melatonin, exercise and diabetes on liver glycogen levels.

BACKGROUND: This study aimed to examine the effects of melatonin supplementation on liver glycogen levels in rats with streptozotocin- induced diabetes and subjected to acute swimming exercise. MATERIAL AND METHODS: Eighty Sprague-Dawley type adult male rats were divided into eight groups: Group 1, general control; Group 2, melatonin-supplemented control; Group 3, melatonin-supplemented diabetes; Group 4, swimming control; Group 5, melatonin-supplemented swimming; Group 6, melatonin-supplemented diabetic swimming; Group 7, diabetic swimming; Group 8, diabetic control. Melatonin was supplemented at a dose of 3 mg/kg/day intraperitoneally for four weeks. Liver tissue samples were collected and evaluated using a Nikon Eclipse E400 light microscope. All images obtained from the light microscope were transferred to PC medium and evaluated using Clemex PE 3.5 image analysis software. RESULTS: The lowest liver glycogen levels in the study were found in group 4. Liver glycogen levels in groups 3, 6, 7 and 8 (the diabetic groups) were higher than group 4, but lower than those in groups 1 and 2. The lowest liver glycogen levels were obtained in groups 1 and 2. CONCLUSIONS: The study indicates that melatonin supplementation maintains the liver glycogen levels that decrease in acute swimming exercise, while induced diabetes prevents this maintenance effect in rats.

Effect of zinc supplementation on the distribution of various elements in the serum of diabetic rats subjected to an acute swimming exercise.

The present study aims to examine the effect of supplementation of zinc on the distribution of various elements in the sera of diabetic rats subjected to an acute swimming exercise. A total of 80 Sprague-Dawley-type adult male rats were equally allocated to one of eight groups: Group 1, general; Group 2, zinc-supplemented; Group 3, zinc-supplemented diabetic; Group 4, swimming control; Group 5, zinc-supplemented swimming; Group 6, zinc-supplemented diabetic swimming; Group 7, diabetic swimming; and Group 8, diabetes. The rats were injected with 40 mg/kg/day subcutaneous streptozotocin (STZ) twice, with a 24-h interval between two injections. Zinc was supplemented at a dose of 6 mg/kg/day (ip) for 4 weeks. Blood samples were collected at the end of the 4-week study, and serum levels of lead, cobalt, molybdenum, chrome, sulfur, magnesium, manganese, sodium, potassium, phosphorus, copper, iron, calcium, zinc, and selenium (mg/L) were determined with atomic emission. The lowest molybdenum, chrome, copper, iron, potassium, magnesium, sodium, phosphorus, lead, selenium, and zinc values were obtained in Group 7 and 8. These same parameters were higher in the swimming exercise group (Group 4), relative to all other groups. The values in zinc-supplemented groups were found lower than the values in Group 4, but higher than those in Group 6 and 7. The results obtained from the study demonstrate that acute swimming exercise and diabetes affect the distribution of various elements in the serum, while zinc supplementation can prevent the negative conditions associated with both exercise and diabetes.

Effect of selenium supplementation on lipid peroxidation, antioxidant enzymes, and lactate levels in rats immediately after acute swimming exercise.

The present study aims to evaluate the effect of selenium supplementation on lipid peroxidation and lactate levels in rats subjected to acute swimming exercise. Thirty-two adult male rats of Sprague-Dawley type were divided into four groups. Group 1, control; group 2, selenium-supplemented; group 3, swimming control; group 4, selenium-supplemented swimming group. The animals in groups 2 and 4 were supplemented with (i.p.) 6 mg/kg/day sodium selenite for 4 weeks. The blood samples taken from the animals by decapitation method were analyzed in terms of erythrocyte-reduced glutathione (GSH), serum glutathione peroxidase (GPx) and superoxide dismutase (SOD), and plasma malondialdehyde (MDA) and lactate using the colorimetric method, and serum selenium values using an atomic emission device. In the study, the highest MDA and lactate values were found in group 3, while the highest GSH, GPx and SOD values were obtained in group 4 (p < 0,001). Group 2 had the highest and group 3 had the lowest selenium levels (p < 0,001). Results of the study indicate that the increase in free radical production and lactate levels due to acute swimming exercise in rats might be offset by selenium supplementation. Selenium supplementation may be important in that it supports the antioxidant system in physical activity.

Effect of intraperitoneal selenium administration on liver glycogen levels in rats subjected to acute forced swimming.

There are a few of studies examining how selenium, which is known to reduce oxidative damage in exercise, influences glucose metabolism and exhaustion in physical activity. The present study aims to examine how selenium administration affects liver glycogen levels in rats subjected to acute swimming exercise. The study included 32 Sprague-Dawley type male rats, which were equally allocated to four groups: Group 1, general control; Group 2; selenium-supplemented control (6 mg/kg/day sodium selenite); Group 3, swimming control; Group 4, selenium-supplemented swimming (6 mg/kg/day sodium selenite). Liver tissue samples collected from the animals at the end of the study were fixed in 95% ethyl alcohol. From the tissue samples buried into paraffin, 5-µm cross-sections were obtained using a microtome, put on a microscope slide, and stained with PAS. Stained preparations were assessed using a Nikon Eclipse E400 light microscope. All images obtained with the light microscope were transferred to a PC and evaluated using Clemex PE 3.5 image analysis software. The highest liver glycogen levels were found in groups 1 and 2 (p < 0.05). The levels in group 4 were lower than those in groups 1 and 2 but higher than the levels in group 3 (p < 0.05). The lowest liver glycogen levels were obtained in group 3 (p < 0.05). Results of the study indicate that liver glycogen levels that decrease in acute swimming exercise can be restored by selenium administration. It can be argued that physiological doses of selenium administration can contribute to performance.