Effect of enkephalin analogues Tyr-D-Ala-Gly-Phe-Cys(Et) and Tyr-D-Ala-Gly-Phe-Cys(Bu) on prolactin and growth hormone release in rats.
The effect of natural Met-enkephalin and its analogues Tyr-D-Ala-Gly-Phe-Cys(Et) (I) and Tyr-D-Ala-Gly-Phe-Cys(Bu) (II) on serum rat prolactin and rat growth hormone levels in male rats has been studied. Met-enkephalin and both analogues increased serum growth hormone and prolactin concentration, analogue I being the most potent. Enkephalin analogue I, with isosteric isomer of methionine in Met-enkephalin, and analogue II with butyl residue showed a lower stimulatory effect than natural Met-enkephalin. Stimulatory effect of analogues I and II on prolactin and growth hormone release was found to be reversed by a simultaneous treatment with the opiate antagonist naloxone.
Nedvídková
J
J
Research Institute of Endocrinology, Praha, Czechoslovakia.
Kasafírek
E
E
Dlabac
A
A
D000818:Animals; D004744:Enkephalin, Methionine / Q000494:pharmacology; D004745:Enkephalins / Q000494:pharmacology*; D013006:Growth Hormone / Q000378:metabolism*; D008297:Male; D011388:Prolactin / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains
D004745:Enkephalins; D004744:Enkephalin, Methionine; D011388:Prolactin; D013006:Growth Hormone; C059272:tyrosyl-alanyl-glycyl-phenylalanyl-cysteine S-ethyl ester; C059273:tyrosyl-alanylglycyl-phenylalanyl-cysteine S-butyl ester