title: Calcium requirement for stimulation of cyclic AMP accumulation in anterior pituitary gland by LH-RH.
abstract: Removal of Ca2+ from the incubation medium by addition of 2 mM ethylene glycol bis-(beta-aminoethyl ether)-N, N'tetraacetic acid (EGTA) leads to at least 75% inhibition of the luteinizing hormone-releasing hormone (LH-RH)-induced accululation of adenosine 3'5'-monophoshpate (cyclic AMP) in rat anterior pituitary gland in vitro. This inhibitory effect of EGTA is reversed by the addition of Ca2+. A half-maximal effect of Ca2+ on LH-RH--induced cyclic AMP accumulation is observed at 2-5 X 10-5 M free Ca2+. The LH-RH-induced LH and FSH release is completely dependent upon the presence of Ca2+ in the incubation medium, a half-maximal effect being measured at 1-2 X 10-4 M free Ca2+. The basal release release of LH is increased upon Ca2+ removal.
mesh_terms: D000818:Animals; D002118:Calcium / Q000494:pharmacology*; D000242:Cyclic AMP / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D004533:Egtazic Acid / Q000494:pharmacology; D005640:Follicle Stimulating Hormone / Q000378:metabolism; D007987:Gonadotropin-Releasing Hormone / Q000494:pharmacology*; D066298:In Vitro Techniques; D007986:Luteinizing Hormone / Q000378:metabolism; D008297:Male; D010902:Pituitary Gland / Q000378:metabolism*; D010903:Pituitary Gland, Anterior / Q000187:drug effects / Q000378:metabolism*; D011863:Radioimmunoassay; D051381:Rats
chemical_list: D007987:Gonadotropin-Releasing Hormone; D004533:Egtazic Acid; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone; D000242:Cyclic AMP; D002118:Calcium