Effect of muscular load on the invertase activity of the small intestine]

Acute experiments were conducted on male albino rats; a study was made of the invertase activity of the proximal, middle and distal portions of the small intestine after a 2-, 4- and 10-hour muscular load in the form of swimming in water at a temperature of 35 +/- 1 degree C. After 2 hours of swimming the invertase activity in the first two portions showed a rather sharp fall; it was restored to the initial level in 48--72 hours. This reduction was much less in the distal portion. Both the 4- and the 10-hour swimming led to an insignificant elevation of the enzymatic activity in all the three portions during 24 hours, with a subsequent decrease in the first two portions and a marked elevation in the distal portion after 48 hours. It is supposed that these changes were realized by means of the hypothalamo-hypophysio-adrenal system by the principle of the common nonspecific adaptive syndrome.