Different effects of K+ and Ca++ on alpha-MSH and ACTH release from superfused neurointermediate lobe of the rat hypophysis.
The effects of K+-enhanced and Ca++-free media on alpha-MSH and adrenocorticotropic hormone (ACTH) release from superfused neurointermediate lobe (NIL) were studied in the same experiments. High K+ caused reversible and repeatable inhibition of alpha-MSH release and stimulation of ACTH release, Removal of Ca++ impaired the effect of K+, irreversibly for alpha-MSH and reversibly for ACTH. The existence of both melanotrophic and corticotrophic cells within the intermediate lobe (IL) of rat hypophysis could account for the different effects of ionic modifications on in vitro alpha-MSH and ACTH release.
D000324:Adrenocorticotropic Hormone / Q000378:metabolism*; D000818:Animals; D002118:Calcium / Q000494:pharmacology*; D008297:Male; D009074:Melanocyte-Stimulating Hormones / Q000378:metabolism*; D010902:Pituitary Gland / Q000378:metabolism*; D011188:Potassium / Q000494:pharmacology*; D051381:Rats
D000324:Adrenocorticotropic Hormone; D009074:Melanocyte-Stimulating Hormones; D011188:Potassium; D002118:Calcium