[The change of nitric oxide to PGE2 ratio in uterine tissues of endotoxin-treated pregnant mice].

Abstract

Objective: To investigate the relationship between preterm labour and the ratio of nitric oxide to prostaglandin E2 in uterine tissues.

Methods: Pregnant mice were given lipopolysaccharide(LPS), LPS + DETA/NO, LPS + DETA or saline solution respectively by intraperitoneal injection on day 16 of gestation. The delivery time of each mouse was recorded. Four separate groups of mice were given treatment as described. And they were killed at 12 hours after that. Serum progesterone, uterine production of nitrite and PGE2 were measured.

Results: Uterin production of nitrite and PGE2 in LPS-treated mice was significantly higher than that in control mice. In contrast the ratio of nitrite to PGE2 decreased. Accompanied by the fall of serum progesterone level DETA/NO rather than DETA could partially reversed the changes.

Conclusion: Infection can induce preterm labor by altering the ratio of nitric oxide to PGE2. Nitric oxide can prevent the decrease of nitric oxide to PGE2 ratio possibly by attenuating the fall of serum progesterone. And it can prevent LPS-induced preterm labor.