The identification of prostaglandins in human umbilical cord.

Abstract

The identification of prostaglandins E1 E2 F1alpha and F2alpha in extracts of umbilical blood vessels is described. Umbilical arteries and veins isolated from about 80 fresh cords were split along their longitudinal axis and washed with distilled water to remove the blood. Due to its high sensitivity guinea-pig proximal colon was used for the routine bioassay of prostaglandins extracted from biological tissues and fluids. The responses of this preparation to the 4 prostaglandins isolated from the umbilical blood vessels are shown in figure form. Fractionation of the final ether extract of umbilical cord vessels on silicic acid column resulted in 4 peaks of biological activity. The main part of the biological activity was present in peaks 2 and 3 eluted with ethyl acetate:benzene (60:40 and 80:20 respectively). The identification of prostaglandins in the umbilical cord vessels shows the distribution of these substances outside the genital sphere. The discovery of these substances in the umbilical and placental vessels raises the issue of their possible physiological role. Because of the action of prostaglandins E2 F1alpha and F2alpha in causing the isolated umbilical artery preparation to contract it is possible that they play a role in the closing of the cord vessels after the fetus is expelled.