The Studies On Level Of Blood Adrenomedullin, Homocysteine, Nitric Oxide And Morphology Of Placenta In Patients With Pregnancy Induced Hypertension

Pregnancy-Induced-Hypertension (PIH) is an important cause of fetal and maternal mortality. The incidency rate of it is 9.4%.Its etiology and pathogenesis are undefined now.Adrenomedullin (AdM) is a potent vasodilating peptide. Recent studies suggest that AdM plays an important role in the regulation of systemic circulation, and promotes smooth muscle relaxation and vasodilation. At present, the experiment in vitro has shown that Hey may act as a inhibitor of aggregation of platelet and as a potent vasoconstrictor by NO releasement. So we examined plasma level of AdM, Hey and serum level of NO in normal late pregnant women and patients with PIH. The aim of this study is to elucidate the role of AdM and Hey and NO in pathophysiologic changes of PIH and provide theroretical foundation of prevention and treatment to PIH.Material and Method: (1)A11 the subjects were divided into Twogroups:(1) the normal late pregnant group (n=20),women with normal late pregnancy; (2) the PIH group(n=60),according to the diagnostic standard(OBSTESTRICS AND GENEOLOGY, the Fifth Edit),it is further subdivided into mild(n=20),moderate (n=20) and severe(n=20) groups. All the patients had no other complications of pregnancy and primary hypertension and other vasculal disorders. There were no significant difference between PIH group and the normal late pregnant group in maternal age and gestational age (p>0.05). (2)The biopsies of placenta were immediately collected after delivery. Tissue was immersion fixed in 10% formalin and embedded in paraffin wax for stain with HE and multimedia image analysis system. (3)The plasma levels of AdM, Hey and serum of NO were measured by radiommunoassay, high performance liquid chromatography and griess reaction respectively.Result: (1) The mean systolic and diastolic blood pressure of three groups of PIH were significantly higher than the normal late pregnant group(p<0.001). (2)Compared with control group pregnant women, plasma AdM in PIH group increased significantly (p<0.05).There were significant difference between mild, moderate and severe PIH groups (p<0.001). (3) The plasma Hey level was significantly in three groups of PIH than those of normal term pregnant women (p<0.05). There were significant difference between mild, moderate and severe PIH groups (p<0.05). (4) Serum NO level in PIH group was significantlylower than that in normal group (p<0.05) , Parallel to disease severity. There were significant difference between mild, moderate, severe PIH groups (p<0.05). (5) Negative correlation was observed between blood AdM level and NO in all groups (r=-0.8111, p<0.001). (6)Negative correlation was observed between blood Hey level and NO in all groups (r=-0.786, p<0.001). (7)The pathological feature of placental in the late trimester was that the number of the villovs with syncytiotrophoblast knots, cytotrophoblastic cells and fibrinoid necrosis of severe PIH were singnificantly higher then that of the normal late pregnant group (p<0.05). While the number of villoas with vasculosyncytial memeranes was significantly lower in sever group ( p<0.05). The parameter of area, circles and diameter of the terminal villous and the percentage of positive area of single field was also significantly lower in severe PIH group (p<0.05).Conclusion: (1) The Plasma levels of AdM were significantly higher in patients with pregnancy-induced-hypertension, and the plasma AdM levels negatively correlated with serum of NO values. (2) The plasma Hey level was higher in three groups of PIH than those of normal term pregnant women (p<0.01). There was significant difference between mild, moderate and severe PIH groups (p<0.01). Negative correlation was observed between blood Hey and NO in pregnancy-induced-hypertension. (3) The area density of terminal villous of severe PIH group was significantly lower than normal group.These results help to study the mechanisms of PIH and provide new theory guide on preventive and therapeutic perspectives.