[Potentiation of ACTH action by a fragment of it: a decrease in the rat adrenal ascorbic acid concentration in vivo].

The effect of tripeptide NH2CO-Arg-Pro-Val-NH2, the analogue of common fragments of some peptide hormones and kinins, on the content of ascorbic acid in rat adrenal glands in vivo is studied. It is shown that the peptide (5 divided by 3000 mkg/100 g body weight) produces no effect on the content of ascorbic acid in adrenal glands, but its injection half an hour before the administration of native ACTH canses a significant increase in the ACTH activity. The peptide possesses the myotropic activity; it exerts sinergism and potentiation of the ACTH action on rat ascending colon.