A study was made of the influence of somatotropic hormone of the hypophysis (STH) on the C14-glucose transport and on the C14-glucose incorporation into the glycogen of the incubated diaphragm of intact rats (group 1), hypophysectomized rats (group 2), rats with alloxan diabetes (group 3), and rats with combined exclusion of the hypophysis and the pancreas functions (group 4). The diaphragm of hypophysectomized rats had an increased capacity to the C14-glucose uptake from the medium and of incorporating it into glycogen, apparently on account of exclusion of the hormones group depending on the hypophysis, with the contrainsular action (STH, ACTH, TTH). On the contrary, the basal rate of the processes studied in the muscles of insulin-deficient rats (group 3) displayed a significant reduction. Alloxan exclusion of the B-cell function in the hypophysectomized rats (group 4) diminished the accelerated glucose transport and glycogen synthesis in the muscle. STH added to the incubation medium stimulated the glucose transport and the glycogen synthesis in the diaphragms of animals with altered endocrine homeostasis (groups 2, 3, 4). Muscles obtained from intact animals were refractory to the STH action. The most STH-sensitive were muscles of hypophysectomized animals (an increase of glucose absorption by 32%, and of C14-glucose incorporation--by 77%). Incubation of the muscles of rats suffering from alloxan diabetes with STH was also accompanied by increased rate of glucose transport and glycogen synthesis; this effect was less pronounced, however. The data obtained indicated that the regulation of carbohydrate metabolism in the muscle tissue with STH was individual, not mediated through any other hormone.