THE PATTERN OF PROGESTERONE SECRETION BY THE AUTOTRANSPLANTED OVARY OF THE EWE IN RESPONSE TO OVINE LUTEINIZING HORMONE

Abstract

SUMMARY The secretion of progesterone from the autotransplanted ovaries of five ewes was measured by a competitive protein-binding technique. Luteinizing hormone (NIH-LH-S14) increased the secretion rate of progesterone from the ovary when infused for 60 min via the ovarian artery at a rate of 1000 μg/h. The pattern of response in nine experiments was characterized by a significant increase in progesterone secretion which occurred 10–20 min after starting the infusion (150%). Between 30 and 60 min the secretion rate fell progressively towards the control values in spite of the continued infusion of LH. There was a further significant fall in the 30 min following cessation of LH. In three out of nine infusions there was a progressive increase in the ovarian blood flow throughout the infusion with maximal levels being found at the end of the 60-min infusion period.