Prostaglandin F2alpha production by the brain and its role in LH secretion.

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 (LH) secretion with estradiol-17beta (E2-17beta). The results indicate that (a) the brain is a significant source of PGF2alpha, (b) the release of PGF2alpha from the brain occurs in pulses with a circhoral rhythm, and (c) the process through which estrogen exerts its negative and positive feedback effects on LH secretion may depend upon amplitude modulation of PGF2alpha output from the brain.