title: Effects of different opiate agonists on melanocyte-stimulating hormone release: in vivo and in vitro studies.
abstract: The effects of Leu-enkephalin, Met-enkephalin, and beta-endorphin on melanocyte-stimulating hormone (MSH) secretion were studied in vivo and in vitro. The three opioid peptides release MSH. In vitro this reslease is dose dependent for Met-enkephalin between 10 and 1000 ng/mL and for Leu-enkephalin between 10 and 100 ng/mL. beta-Endorphin releases MSH at the low concentration of 1 ng/mL and the effect is dose dependent between 1 and 100 ng/mL. Naloxone reverses this effect. In vivo the three petptides release MSH.
mesh_terms: D000818:Animals; D004723:Endorphins / Q000494:pharmacology*; D004745:Enkephalins / Q000494:pharmacology*; D066298:In Vitro Techniques; D008297:Male; D009074:Melanocyte-Stimulating Hormones / Q000378:metabolism*; D009270:Naloxone / Q000494:pharmacology; D010902:Pituitary Gland / Q000187:drug effects* / Q000378:metabolism; D051381:Rats
chemical_list: D004723:Endorphins; D004745:Enkephalins; D009270:Naloxone; D009074:Melanocyte-Stimulating Hormones