Arginine and Aerobic Training Prevent Impairment in Endothelial Function in Rats Under High Risk to Develop Metabolic Syndrome

Abstract

It is not elucidated if aerobic training and arginine supplementation can have similar protective effects in individuals with constant exposure to the triggering agent of the metabolic syndrome, with the presence of subclinical alterations, but without the presence of cardiovascular disease. So the purpose of this study was to investigate the effect of arginine supplementation and aerobic training on vascular reactivity of rats under high risk of metabolic syndrome development. Wistar rats, males, adults were, initially, divided in two groups Control group (C; drinking water) and Fructose group (F; water with 10% fructose), after two weeks the F group was divided into four others groups: Fructose group (F), that continued with the same treatment, Fructose Arginine group (FA), Fructose Training group (FT) and Fructose Training Arginine group (FTA) same as F group, adding aerobic training on a treadmill and/or arginine supplementation by gavage (800mg/kg BM/day), in the last 8 weeks. There were no differences in body mass gain and caloric intake between groups (P>0.05). It was observed higher serum insulin in F group compared to control group after two (P=0.046) and ten weeks (P=0.014), while it was not observed any difference between the other groups compared to C group. In relation to serum triacylglycerol levels, after two weeks, there was no difference (P=0.154) between C and F groups. After ten weeks the F group presented higher triacylglycerol concentration (P<0.01) compared to C group and the training normalized this increased, however arginine supplementation had no effect on this parameter. The malondialdehyde serum concentration, an oxidative stress marked, had the same pattern as the triacylglycerol. Concerning vascular reactivity, there was no difference after two weeks of treatment. While at the end of protocol, the F group exhibited increased vasoconstrictory reactivity (P<0.01) to phenylephrine when compared to C and to trained groups (FT and FTA). The F group also presented an impaired endothelial vasodilator response to acetylcholine compared to other groups and the arginine supplementation and the aerobic training were able to prevent this impaired response. Thus aerobic training prevents the metabolic alterations, the hypereactivity to phenylephrine and the endothelial damage of rats with high risk to develop metabolic syndrome, while arginine supplementation was capable only to prevent the endothelial damage in this experimental model, with no potentiating effect.Support or Funding InformationCAPES, CNPq, FAPERJ e FINEP.