Effect of muscular exertion on invertase activity of the small intestine

Abstract

Invertase activity of the proximal, middle, and distal parts of the small intestine after muscular exertion lasting 2, 4, and 10 h (forced swimming in water at 35±1°C) was studied in acute experiments on male albino rats. After swimming for 2 h the invertase activity in the first two parts of the intestine was sharply reduced and it returned to its initial level after 48–72 h. This decrease was much less marked in the distal portion. Swimming for both 4 and 10 h led to a slight increase in enzyme activity in all three parts of the intestine 24 h after the beginning of the experiments, followed by a decrease in the first two parts and a marked increase in the distal portion 48 h after the beginning of the experiment. It is suggested that these changes are brought about through the hypothalamic-pituitary-adrenal system in accordance with the principle of the general nonspecific adaptation syndrome.