Stimulation of prolactin release in rats by GABA.

Infusion of GABA into the lateral ventricle of intact female rats on the morning of proestrus and in ovariectomized rats significantly stimulated PRL release. This response apparently is not mediated through a direct action on the pituitary since injection of GABA into hypophysectomized rats with a pituitary transplant under the kindney capsule did not alter serum prolactin levels. These observations suggest that GABA may have a role in regulating prolactin secretion.