The Action of Prostaglandins on the Human Isolated Non‐pregnant Cervix

Abstract

Summary The isolated non‐pregnant cervix has been shown to exhibit spontaneous isotonic and isometric contractility and to respond to drugs. PGE2 causes a marked relaxation whilst the effect of PGF2α is more variable. Oxytocin and adrenaline cause contraction of the muscle. The implications of the finding that the cervix can show isotonic and isometric contractility and the effects of prostaglandins are discussed.

Ripening of the Uterine Cervix and Induction of Labour at Term with Prostaglandin E2 in Viscous Gel

“…Studies by Coutinho & Darze (1976) on cervical mechanical activity in vivo suggest that PGE, has a direct relaxing effect of the smooth muscle of the non-pregnant uterine cervix. This agrees with in vitro studies by Najak et al (1970) which showed that spontaneous contractile activity of the cervical muscle layer was increased by PGF,. and decreased by PGE,.…”

The Effect of Oxytocics on the Human Cervix During Midtrimester Pregnancy

“…The results obtained for the prostaglandins differed from the in vitro study of Najak et al (1970), who found that PGF,a caused a large percentage of non pregnant cervical tissue specimens to contract while PGE, caused them to relax. It is possible that the variation between their results and those of the present study could be explained by the differences in the experimental techniques employed or probably by the effect that the hormonal milieu of pregnancy has upon the sensitivity of the cervix to the drugs investigated.…”

Combined bladder and uterine rupture following prostaglandin‐induced midtrimester abortion: an unreported event

“…In the series by Wentz et al it was clinically observed that the cervix felt more rigid during prostaglandin F 2α ‐induced abortions than with hypertonic saline (4). This has also been confirmed by experiments by Najak et al, where strips of pregnant cervix contracted by administration of prostaglandin F 2α whereas prostaglandin E 2 caused their relaxation (8). If prostaglandin F 2α does indeed cause even a small amount of cervical contraction, then it may not be a suitable agent for midtrimester abortion because of its inability to control the force of uterine contractions in the presence of a resistant cervix.…”