Effect of swimming exercise on lipid peroxidation, leptin-insulin axis and brain Na+-K+-ATPase enzymatic activity in rats

ABSTRACT

Several authors suggest that the leptin-insulin axis functions as the afferent limb of a negative feed-back loop that provides sensory input to the hypothalamus about energy balance and body weight. Aim: The objective of this work was to study the effect of acute swimming exercise versus chronic swimming exercise program on blood glucose, adiposity and insulin resistance indices, and lipid peroxides levels as an important effect of exercise is the production of lipid peroxides which can modulate insulin and leptin action. Also, brain sodium-potassium-adenosine triphosphatase [Na[+]-K[+]-ATPase] was determined as it is an important modulator of leptin and insulin action in the hypothalamus. 36 adult rats were used in this study divided into 3 groups, each of 12 rats. Group I is the control sedentary group, group II acute swimming rats and group III chronic swimming rats. Mean serum glucose, insulin and leptin levels, insulin resistance and adiposity indices were significantly decreased while serum lipid peroxides was significantly elevated in group Ill compared to both groups I and II. Brain Na[+]-K[+]-ATPase enzymatic activity was significantly decreased in both groups II and III. Insulin was positively correlated with insulin resistance index in both groups [I and II] and leptin in group III. chronic swimming exercise training exerted beneficial effects by reducing body fat index, blood glucose and leptin, improving insulin sensitivity, brain Na[+]-K[+]-ATPase enzymatic activity and hence cognitive function. On the other hand, short strenuous exercise increased serum lipid peroxides [MDA], Serum glucose, thereby inducing oxidative stress