2-Hydroxysaclofen, a potent GABAB receptor antagonist, stimulates luteinizing hormone secretion in female rats

An intraventricular injection of a potent GABAB receptor antagonist, 2-hydroxysaclofen, elicited luteinizing hormone (LH) secretion in a dose-dependent manner under the negative feedback condition in ovariectomized estrogen-primed rats. Significant reduction of the effect of 2-hydroxysaclofen by baclofen, a selective GABAB agonist, suggested that the antagonist stimulated LH secretion through interaction with the GABAB receptor. These results provide evidence that the endogenous GABA acting at the GABAB receptor plays a physiological role in controlling basal LH secretion.