Enhanced prolactin release by injection of glycine in the medial preoptic area (mPOA) of the rat.

Injection of glycine into the medial preoptic area (mPOA) in doses of 12.5, 25 and 50 micrograms produced a marked increase in prolactin release in freely-moving male rats. Neither taurine nor beta-alanine had effect on prolactin. These amino acids were unable to modify the resting plasma LH levels. The present studies show that the mPOA is a target site for the prolactin releasing action of glycine. Furthermore, they suggest a participation of this amino acid in the mPOA mechanism for control of prolactin secretion in the rat.