Assessment of possible luteolytic effect of intra-ovarian injection of prostaglandin F2α in the human

A group of five patients awaiting laparoscopic tubal diathermy were followed by daily assay of luteinising hormone (LH) and progesterone. Between five and eight days after the LH peak, prostaglandin F_2α (PGF_2α) was injected into either the corpus luteum or the ovarian stroma. Doses of 100 μg into the corpus luteum, 1000 μg into the adjacent stroma and 500 μg into an indeterminate ovarian structure had no effect on peripheral plasma progesterone levels or uterine bleeding.An injection of 500 μg or 1000 μg given unequivocally into the corpus luteum produced a rapid and profound fall in plasma progesterone levels, the nadir coinciding with the onset of uterine bleeding which commenced 24 hours after the injection and persisted for more than seven days. Injection of 100 μg in the same volume of saline had no such effect. Despite continued bleeding plasma progesterone levels returned to normal luteal levels for three days and then fell again.