Release of beta-lipotropin and beta-endorphin from rat hypothalami in vitro.
Hypothalamic tissue extracts of rats were chromatographed and beta-endorphin immunoreactivity (beta-Endi) was measured. The two major peaks of beta-Endi co-eluted with beta-lipotropin (beta-LPH) and beta-End respectively. Hypophysectomy caused a local decrease of beta-LPH and beta-End concentrations in the mediobasal hypothalamus. During superfusion of hypothalamic tissue blocks in vitro, membrane depolarization by electric stimulation or 45 mM k+ induced a Ca2+-dependent release of both beta-LPH and beta-End.
D000818:Animals; D002118:Calcium / Q000494:pharmacology; D004558:Electric Stimulation; D004723:Endorphins / Q000378:metabolism*; D007016:Hypophysectomy; D007031:Hypothalamus / Q000187:drug effects / Q000378:metabolism*; D066298:In Vitro Techniques; D008297:Male; D008564:Membrane Potentials / Q000187:drug effects; D010477:Perfusion; D011188:Potassium / Q000494:pharmacology; D051381:Rats; D008083:beta-Lipotropin / Q000378:metabolism*
D004723:Endorphins; D008083:beta-Lipotropin; D011188:Potassium; D002118:Calcium