The central actions of glycine and strychnine on prolactin and LH secretion.
Unanesthetized diestrous female rats were tested for the prolactin response following an intraventricular injection of several doses of the neuroinhibitory amino acid glycine, and the antagonist strychnine. Glycine in doses of 1.0 or 0.1 mumoles increased pituitary prolactin release, significantly elevating plasma hormone levels. Direct pituitary effects for glycine were not observed. Strychnine, a glycine antagonist, was effective in blocking the prolactin release caused by glycine in doses as low as 5 nmoles. Intraventricular glycine administration did not alter pituitary LH release significantly. These studies suggest a central stimulatory role for the neuroinhibitory amino acid glycine in provoking prolactin secretion, and that this effect is strychnine sensitive.
D000818:Animals; D004336:Drug Antagonism; D005260:Female; D005998:Glycine / Q000008:administration & dosage / Q000494:pharmacology*; D007276:Injections, Intraventricular; D007700:Kinetics; D007986:Luteinizing Hormone / Q000378:metabolism*; D011388:Prolactin / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D013331:Strychnine / Q000494:pharmacology*
D011388:Prolactin; D007986:Luteinizing Hormone; D013331:Strychnine; D005998:Glycine