Effect of beta-casomorphin and its analogue on serum prolactin in the rat.
The effects of exogenous opioid peptides beta-casomorphin Tyr-Pro-Phe-Pro-Gly-Pro-Ile and its analogue Tyr-Pro-Gly-Pro-Phe-Pro-Ile (analogue I) were found to increase prolactin level in plasma after intraperitoneal injection. Analogue I was more potent. This effect of beta-casomorphin and analogue I were blocked by an opioid antagonist, naloxone. These results indicate that the exogenous opioid peptides (exorphins) may participate in the regulation of prolactin secretion. The similarity of analogue I with enkephalin structure was discussed.
D000818:Animals; D002364:Caseins / Q000494:pharmacology*; D004723:Endorphins / Q000494:pharmacology*; D008297:Male; D009020:Morphine / Q000494:pharmacology; D009270:Naloxone / Q000494:pharmacology; D010446:Peptide Fragments; D011388:Prolactin / Q000097:blood*; D051381:Rats; D011919:Rats, Inbred Strains
D002364:Caseins; D004723:Endorphins; D010446:Peptide Fragments; D009270:Naloxone; D009020:Morphine; C021968:beta-casomorphins; D011388:Prolactin; C046260:beta-casomorphin I