The Changes Of The Vasoactive Factors In Normal Pregnancy And Pregnancy Induced Hypertension

Part I The changes of vasoactive factors in normalpregnancy ABSTRACTOBJECTIVE: This study is performed to observe the changes of plasma vasoactive factors in each labor stage of normal pregnant woman, compared with normal nonpregnant woman of reproductive age. And it was also investigated the effects of these factors in the normal pregnancy. METHODS: 1 > The studies were performed in normal healthy nonpregnant women (n=20)N normal pregnant women (n=20). 2^ Blood samples were collected before first labor stage, on the second labor stage and 24 hours after parturition on each pregnant woman. Both blood of the artery and vein in umbilical cord vessel were also collected. On normal nonpregnant women, the blood samples were collected on their nonmenstruation days. 3 > NPY, E^ TXA2> PGI2 > vWF> NO were analyzed by radioimmunoassay enzyme-linked immunoassay and Griess assay. RESULTS: 1, NO significantly increased in normal pregnant women compared with nonpregnant women, P<0.05,while the other factors were had no statistical significance between normal pregnant and nonpregnant women,P>0.05.2; At the second stage of the labor ET, vWF> NPY, TXA2 raised significantly and decreased after delivery. P<0.05. PGI2 was stable during the labor but decreased after delivery, P<0.05. NO decreased significantly at the second stage of the labor, P<0.05. 3^ TXA^ ET in normal pregnant women were increased in the umbilical cord vessel while PGI2 were decreased on the contrary. P<0.05. NO raised in the artery of umbilical cord and decreased in the vein of the umbilical cord, P<0.05. CONCLUSING: K Because of no effects of oxygen deficiency and vascular injured , thevasoactive factors such as NPY, vWF, ET, TXA2, PGI2 have no significant changes between pregnant and nonpregnant woman. NO which acts as an inside vessel relaxation factor has it another function to keep the peace of the uterus, it's concentration decreased gradually during the third term of pregnancy, and labor will start when its concentration decreased to the threshold. 2, The vessel contraction factors such as ET\ vWF > NPY^ TXA2 raised in the second stage of labor, one of the possible reasons is when labor starting ,the exciting of nervous increased which enhanced the construction of the vascular and regular contraction of uterus caused the transient oxygen deficient. And because of the construction of the uterus, the fetus secreted more vascular contraction factors and less relaxation factors. These may lead to the high ratio of fetal distress in the second stage of labor.