[Effect of whale somatotropin and its biologically active fragment on various indicators of carbohydrate metabolism in the rat diaphragm in vitro].

The ability of somatotropin seival and its fragment 77-107, retaining a marked growth-stimulationg activity, to change the intensity of 14C-glucose consumption from the medium and 14C-glucose inclusion into glycogen by in vitro incubated semidiaphragm of hypophysectomized rats was studied. It was detected that somatotropin seival, contacting with the diaphragmatic muscle tissue, provokes "insulin-like" effect. (i.e. stimulates glucose consumption and glycogen synthesis by this tissue), similar to that of the other animal somatotropins studied. Somatotropin fragment 77-107, revealing growth-stimulating activity, is not able to intensify glucose consumption and glycogen synthesis in the muscle tissue, in contrast to the whole hormone, being indicative of dissociation between structural determinants of these effects in hormone molecule.