[The changes of plasma nitric oxide in patients with pregnancy induced hypertension].

OBJECTIVE: To determine whether the antepartum and postpartum plasma nitric oxide (NO) levels were changed in pregnancy induced hypertension (PIH). METHODS: 30 patients with PIH and 30 healthy women in their late pregnancy were studied. The antepartum and postpartum plasma NO2-/NO2- levels, the stable metabolic end products of NO, and cyclic guanosine monophosphate (cGMP) were measured with greiss reagent. RESULTS: (1) The plasma concentration of NO2-/NO2- and cGMP in patients with PIH decreased significantly when compared with that of healthy pregnant women (P < 0.01). (2) The concentration of antepartum plasma NO2-/NO2- was markedly lower than that of postpartum one in PIH patients (P < 0.01). (3) There was a negative correlation between the plasma NO2-/NO3- level and systolic blood pressure in PIH (P < 0.01). (4) A positive correlation was seen between plasma NO2-/NO3- levels and cGMP levels in PIH patients (P < 0.01). CONCLUSION: The decrease of NO synthesis may be one of the important factors responsible for PIH.