Investigation On Expression Of Endothelial Nitric Oxide Synthase MRNA And Changing Of Nitric Oxide Concentration In Placental Tissue Of Pregnancy-induced Hypertension Syndrome

Pregnancy-induced hypertension syndrome PIH) is one of the important diseases seriously endangering the pregnant mother and fetus. Etiology and pathogenesis of PIH is continuously the major topic of study in obstetrics. In view of the conditions of patients with PIH recover rapidly after pregnancy termination with placenta deliveried, it implies that placenta might be play a crucial role in PIH.Therefore, it is very important to study placentae for revealing the etiology and pathogenesis of PIH . In this study, 30 placentae from pregnancy-induced hypertension syndrome were collected among the patients admitted to our hospital from 1999,8-2001,7. The placentae were examined for the expression of eNOS mRNA by reverse transcription-polymerase chain reaction (RT-PCR) and the level of NO by nitrate reductase , compared with that of 30 placentae from normal term pregnancies (NTP) during the same period . The correlation between these two parameters was evaluated. The results were as follows :1. In placental tissues of PIH , the expression intensity of eNOS mRNA and the concentration of NO decreased significantly compared with that of NTP (P<0. 05) ;2. There were no differences in the expression intensity of eNOS mRNA and the concentration of NO in placentae between---- 2 ---mild PIH and NTP(P>0. 05) ;but in moderate and severe PIH , they decreased significantly compared with that in NTP and mild PIH(P<0. 05).3. There was a positive correlation between the expression intensity of eNOS mRNA and the concentration of NO in placental tissues. The correlation coefficient is 0.8362(P<0. 05).Conclusions: Nitric oxide system showed obvious changes in PIH, leading to the increased rate of maternal and neonatal morbidity and mortality. It also suggested that the development of PIH may be the result of interaction of multi-factors. Endothelial cell dysfunction may play an important role in etiology of PIH.