Release of beta-endorphin from rat pituitary in vitro.
The rate of release of beta-endorphin immunoreactivity from the anterior lobe of the rat pituitary in vitro increased in respone to potassium-induced depolarization in a calcium-dependent manner. Potassium-induced depolarization did not, however, change the rate of release from intermediate/posterior lobe. These findings provide support for the view that beta-endorphin may have a humoral function and suggest that beta-endorphin stores in discrete pituitary areas are regulated by different release mechanisms.
D000818:Animals; D002118:Calcium / Q000502:physiology; D004723:Endorphins / Q000276:immunology / Q000378:metabolism*; D066298:In Vitro Techniques; D008297:Male; D010902:Pituitary Gland / Q000378:metabolism*; D011188:Potassium / Q000494:pharmacology; D011817:Rabbits / Q000276:immunology; D011863:Radioimmunoassay; D051381:Rats
D004723:Endorphins; D011188:Potassium; D002118:Calcium