[Molecular mechanisms of hypothalamic hexapeptide regulation of the links in glycogen metabolism]

Alterations in content of glycogen as well as in activity of phosphorylase and phosphoprotein phosphatase were studied in various rat tissues after intravenous administration of a new hypothalamic hexapeptide Tyr-Gly-Leu-Pro-Gly-NH2. An increase in phosphoprotein phosphatase activity was observed in heart muscle, which correlated with transformation of phosphorylase A to the B form and with accumulation of glycogen. The opposite effect was found in liver tissue and sceletal muscle.