Elevated cardiac oxidative stress in newborn rats from mothers treated with atosiban

The purpose of this study was to evaluate the cardiac and cerebral oxidative stress in the offspings of pregnant rats treated with oxytocin antagonist atosiban.

Experimentally naive, adult female Wistar-albino rats (200-250 g) were mated with adult male rats for copulation. After confirming pregnancy, eight gravid rats were then randomly assigned into two equal groups. The animals were treated from days 15 to 20 of gestation. One group acted as a control group, and received intraperitoneal (i.p.) injections of saline in a daily dose volume of 6 mg/kg/day. The second group received 6 mg/kg/day i.p. atosiban. On day 21 of gestation, pups were delivered by cesarean. The heart and brain tissues of the newborn rats were dissected and sent for the measurement of total oxidant status, total antioxitant status and oxidative stress index.

There was no significant difference in birthweight or in the number of pups between two groups. Newborns from atosiban-treated mothers showed significantly increased oxidative stress in the plasma and heart tissue than that of controls which was confirmed by histological examination (P < 0.05). Oxidative stress parameters and histopathological results of the brain tissues of newborns were similar between two groups (P > 0.05).

Oxytocin receptor blockage for the treatment of premature delivery may be associated with increased fetal morbidity and mortality secondary to the elevated oxidative stress in the heart of the newborns.