Prostaglandin F2alpha production by the brain during estrogen-induced secretion of luteinizing hormone

The arteriovenous difference in the concentration of prostaglandin F2alpha (PGF2alpha) across the brain of the anestrous sheep was measured before and during the induction of luteinizing hormone secretion with 17 beta-estradiol. The results indicate that (i) the brain in vivo is a significant source of PGF2alpha, (ii) the release of PGF2alpha from the brain occurs in pulses with a circhoral rhythm, and (iii) the process through which estrogen exerts its negative and positive feedback effects on luteinizing hormone secretion may involve amplitude modulation of PGF2alpha output from the brain.