Assessment of the role of G proteins and inositol phosphate production in the action of gonadotropin-releasing hormone.
The first step in gonadotropin-releasing hormone (GnRH) action involves the binding of GnRH to a plasma membrane receptor. Calcium has been implicated as a second messenger molecule. More recently, it has been suggested that the products of phosphoinositide metabolism may act as a second messenger for GnRH-stimulated release of luteinizing hormone (LH). To be considered a second messenger, however, a candidate molecule must meet three requirements: in the second messenger's presence, (a) GnRH should stimulate increased production of inositol phosphate; (b) inositol phosphate production, stimulated by any means, should provoke LH release; and (c) inhibition of inositol phosphate production should block GnRH-stimulated release of LH.
Hawes
B E
BE
Department of Pharmacology, University of Iowa College of Medicine, Iowa City 52242-1109.
Conn
P M
PM
D000818:Animals; D002118:Calcium / Q000502:physiology; D019204:GTP-Binding Proteins / Q000502:physiology*; D007987:Gonadotropin-Releasing Hormone / Q000502:physiology*; D006801:Humans; D007295:Inositol Phosphates / Q000096:biosynthesis*; D007986:Luteinizing Hormone / Q000378:metabolism; D011493:Protein Kinase C / Q000378:metabolism; D015290:Second Messenger Systems; D012969:Sodium Fluoride / Q000494:pharmacology
D007295:Inositol Phosphates; D007987:Gonadotropin-Releasing Hormone; D012969:Sodium Fluoride; D007986:Luteinizing Hormone; D011493:Protein Kinase C; D019204:GTP-Binding Proteins; D002118:Calcium