Effect of hydrogen peroxide on prostaglandin production and contractions of the pregnant rat uterus

Although evidence for a role for prostaglandins in parturition is abundant, less is known about how prostaglandin levels are regulated at term. Conditions occurring peripartum in the uteroplacental unit can result in reactive oxygen production. We investigated the effect of one reactive oxygen product, hydrogen peroxide, on in vitro activity of uterine segments from the 18-day-pregnant rat. H2O2 (0.3 mmol/L) was found to elicit rhythmic contractions and increase prostaglandins F2 alpha and E2 release by uterine tissue. Indomethacin blocked both of these effects. We conclude that H2O2 stimulates uterine contractions through a prostaglandin release mechanism. A speculative hypothesis of peripartum regulation of prostaglandin production by reactive oxygen is discussed.