The Contractile Response of the Human Uterus, Fallopian Tubes, and Ovary to Prostaglandins in Vivo

Abstract

In vivo studies were carried out in 8 women to ascertain the effects of prostaglandins (PGs) E2 and F2alpha on the human fallopian tubes and ovaries. Recording devices were surgically implanted into the tubal lumen through catheters. 100 mcg. of either PGE2 or PGF2alpha or a mixture of equal amounts of the 2 totaling 100 mcg. were administered intravenously and the effects recorded. Graphs of the effects are presented. The 2 pure substances and the mixture all had a stimulatory effect on the uterus at all phases of the menstrual cycle. There were, however, qualitative and potency differences between PGE2 and PGF2alpha. On a weight basis, PGE2 had more powerful effects on the myometrium. The 2 PGs had opposing effects on the fallopian tubes, with PGF2alpha stimulating while PGE2 inhibited tubal motility. A contractile response of the ovary following intravenous administration of PGF2alpha was noted; no change in intraovarian pressure was recorded following injection of up to 100 mcg. PGE2. The compound was mildly stimulatory. The ability of PGE2 to induce relaxation of the tubes while stimulating uterine activity provides a clue as to why it is more effective in inducing abortion than PGF2alpha. It is suggested that relaxation of the tubal isthmus induced by seminal PGE2 facilitates sperm penetration into the tube.