Nitric oxide and iron metabolism in exercised rat with L-arginine supplementation.
ABSTRACT The present study was designed to investigate whether L-arginine (Arg) supplementation in exercise affects nitric oxide (NO) synthesis in tissues and thus iron metabolism. Rats were assigned to one of four groups: EG (Exercise), SG (Sedentary), EAG (Exercise + Arg), and SAG (Sedentary + Arg). Both EG and EAG swam 2 h/day for 3 months. Both SAG and EAG received 3% Arg supplementation in their drinking water. The results showed that Arg supplementation in exercise (EAG) significantly increased nitrite and nitrate (NOx) concentration in the kidney and BMC, rather than in the liver, spleen and heart. Arg supplementation significantly increased both nonheme iron (NHI) and catalytic iron (CI) content in the kidney, to the extent that the ratio of CI/NHI or storage iron (SI)/NHI was not significantly affected, and significantly decreased NHI content and increased CI content in BMC, to the extent that SI content or SI/NHI was significantly decreased. These findings suggest that Arg supplementation in exercise, possibly through increasing NO synthesis, may change CI formation in the kidney and BMC, and affect iron storage in BMC rather than in the kidney.
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ABSTRACT: • This study shows:• No effects of combined supplementation of L-arginine and nitrate or nitrate alone on exercise economy• No effects of combined supplementation of L-arginine and nitrate on sprint performance• No effects of combined supplementation of L-arginine and nitrate or nitrate alone on endurance performance• However, plasma nitrate and nitrite concentrations with combined L-arginine and nitrate and nitrate alone were significantly elevated compared to placeboNitric Oxide 10/2014; DOI:10.1016/j.niox.2014.10.006 · 3.18 Impact Factor
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ABSTRACT: The present study was to investigate the effects of l-arginine (l-Arg) supplementation on cardiac oxidative stress and the inflammatory response in rats following acute exhaustive exercise on a treadmill. Rats were randomly divided into four groups: sedentary control (SC); SC with l-Arg treatment (SC+Arg); exhaustive exercise (E); exhaustive exercise with l-Arg treatment (E+Arg). Rats in groups SC+Arg and E+Arg received a 2 % l-Arg diet. Rats in groups E and E+Arg performed an exhaustive running test on a treadmill at a final speed of 30 m/min, 10 % grade, at approximately 70-75 % VO2max. The results showed a significant increase in cardiac xanthine oxidase (XO) and myeloperoxidase activities and membrane lipid peroxidation endproduct (malondialdehyde; MDA) levels of exercised rats compared with SC rats. The increased cardiac XO activity and MDA levels in exercised rats were significantly decreased in exercised rats supplemented with l-Arg. Myocardial GSSG content increased whereas the GSH:GSSG ratio was depressed in exercised rats compared with SC rats. Cardiac GSSG levels significantly decreased, whereas total glutathione, GSH and the GSH:GSSG ratio increased in exercised rats supplemented with l-Arg compared with exercised rats. The activities of creatinine kinase (CK) and lactate dehydrogenase (LDH), and lactate, uric acid, and nitrite and nitrate levels in the plasma significantly increased in exercised rats compared with SC rats. The activities of plasma CK and LDH were significantly decreased in l-Arg-supplemented plus exercised rats compared with exercised rats. These findings suggest that l-Arg supplementation reduces the oxidative damage and inflammatory response on the myocardium caused by exhaustive exercise in rats.British Journal Of Nutrition 02/2006; 95(1):67-75. DOI:10.1079/BJN20051602 · 3.34 Impact Factor
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ABSTRACT: Although iron plays a critical role in exercise, the regulatory mechanism of iron metabolism remains poorly understood. The aims of the present study were to investigate the effects of different intensity exercise on body iron status and the regulatory mechanism of duodenal iron absorption. Thirty female Sprague-Dawley rats (90-100 g) were randomly divided into three groups: a control group (remained sedentary, CG), a moderately exercised group (swam 1.5 h/day, MG) and a strenuously exercised group (swam with different load, SG). Serum iron status, serum ferritin and Hct were examined after 10 weeks of swimming. Western blot was performed to detect the expression of iron transport proteins: divalent metal transporter1 (DMT1) and ferroportin 1 (FPN1) in duodenal epithelium. The expression of hepcidin mRNA in liver was examined by RT-PCR. The results showed: (1) the body iron status in MG was kept at a high level compared to that of CG and SG, (2) Western blot showed DMT1 with iron responsive element (IRE) and FPN1 in duodenal epithelium which were higher in MG than that of CG and (3) the expression of hepatic hepcidin mRNA was down regulated in MG (p < 0.05). The data suggested that moderate exercise improved iron status and that was likely regulated by increased DMT1 with IRE and FPN1 expression. Hepcidin signaling pathway may involve in the regulation of duodenal iron absorption proteins.Molecular and Cellular Biochemistry 01/2006; 282(1-2):117-23. DOI:10.1007/s11010-006-1522-4 · 2.39 Impact Factor