Changes in ovarian and pituitary function in non-pregnant women during the infusion of prostaglandin F2alpha.

The concentrations of prostaglandin F2alpha, progesterone, oestradiol, LH and cortisol have been determined in serial samples of peripheral venous plasma, before, during and after, the intravenous administration of prostaglandin F2alpha (50 mug/min, for 5 h) to 8 women in the luteal phase of the ovarian cycle. The results show that the mean concentrations of prostaglandin F2alpha and cortisol increased during the infusion by factors of 8.8 and 2.6 respectively. The highest levels of cortisol occurred after 3 h, and were significantly different (P less than 0.0005, Student's t-test) from those obtained before the infusion. There were progressive decreases in the concentrations of LH and progesterone. After 3 h the values for LH were significantly lower (P less than 0.0025) than those before the administration of prostaglandin F2alpha, and the lowest mean value was 26% of the control. The values for progesterone were significantly lower (P less than 0.025) after 5 h, and the mean value at this time was 38% of the control. The pattern of the mean concentration for oestradiol was similar to that for progesterone. The levels of all 5 compounds had returned to normal within 1 h after completion of the infusion. The findings are discussed.