Effect Of Mifepristone On The Ultrastructure Of Human Fetal Umbilical Vein And ER,PR,ET-1 And ENOS

PurposeThe influence of mifepristone on the ultrastructure and estradiol receptor(ER), progesterone receptor(PR) ,endothelin-1(ET-1) and endothelial nitric oxide synthase(eNOS) of fetal umbilical vein were studied by means of TEM observation and immunohistochemical technology respectively.Methods20 pregnant women with indication for pregnancy termination were recruited and randomly divided into 2 groups(each group for 10). In mifepristone group,ISOmg mifepristone per os was given six hours before labor was induced. Labor induction was performed by extra-amniotic insertion of waterbag in the control group. Immediately after delivery of fetus ,umbilical vein was acquired and prepared for transmission electron microscopic(6 case for each group) observation and immunohistochemical examination.Result1. In comparison with the control groups, the umbilical vein of mifepristone group displayed the following morphological changes: (1) endothelial cell: the cytoplasm was vacuolated , even broken; in the rough endoplasmic reticulum ,vacuolization was found. (2) vascular smooth muscle cell: the chromatin was condensed and marginated and perinuclear space was dilated; mitochondria were vacuolated; glycogen granules in cytoplasm were reduced in number or disappeared (3) the interstitial tissue was oedema.2. The immunostaining intensity of progesterone receptor in umbilical vein was decreased significantly (34. 38 ± 4. 70vs20. 87 ± 5. 55 , P<0.05) after mifepristone administered and the estrogen receptor wasincreased significantly (18. 44 + 4. 51vs34. 39 + 4. 80, P<0.05). 3. The immunostaining intensity of endothelial nitric oxide synthase in umbilical vein was decreased significantly (18. 66 + 5. 78vs33. 81 + 7. 36, P<0.05) after mifepristone administered and the endothelin-1 was increased significantly (25. 39±10. 35vsl6. 00±3. 25, P<0.05).ConclusionMifepristone can cause a hypoxic damage in the second trimester fetal umbilical vein and may decrease the fetal blood flow.