Release of dynorphin-like immunoreactivity from rat anterior pituitary gland in vitro.
Rat anterior pituitary quarters were incubated in vitro and the release of dynorphin A1-13-like immunoreactivity (Dyn A1-13-IR) into the incubation medium was studied. An elevation of the potassium concentration of the incubation medium to 40 mmol/l increased the release of Dyn A1-13-IR in a calcium-dependent manner. Addition of luteinizing hormone-releasing hormone (LHRH) stimulated the release of Dyn A1-13-IR in a dose-dependent manner. The LHRH-induced release of Dyn A1-13-IR was almost completely prevented by omission of calcium ions from the incubation medium or by addition of the LHRH-antagonist D-pGlu1,D-Phe2,D-Trp3,6-LHRH. This is the first demonstration that dynorphin-like immunoreactivity can be released from the rat adenohypophysis through calcium-dependent mechanisms by both high potassium concentration and receptor-mediated stimulation.
Knepel
W
W
Schwaninger
M
M
D000818:Animals; D002118:Calcium / Q000502:physiology; D004399:Dynorphins / Q000378:metabolism*; D007987:Gonadotropin-Releasing Hormone / Q000037:antagonists & inhibitors / Q000494:pharmacology; D066298:In Vitro Techniques; D008297:Male; D010446:Peptide Fragments / Q000378:metabolism; D010903:Pituitary Gland, Anterior / Q000378:metabolism*; D011188:Potassium / Q000502:physiology; D011863:Radioimmunoassay; D051381:Rats; D011919:Rats, Inbred Strains
D010446:Peptide Fragments; D007987:Gonadotropin-Releasing Hormone; C026843:dynorphin (1-13); D004399:Dynorphins; D011188:Potassium; D002118:Calcium