thromboplastin and Placenta-Diseases

During normal pregnancy, the renin-angiotensin system (RAS) plays a vitally important role in salt balance and subsequent well-being of mother and fetus. In this balance, one must consider not only the classical renal RAS but also that of the uteroplacental unit, where both maternal and fetal tissues contribute to the signaling cascade. Many studies have shown that in normal pregnancy there is an increase in almost all of the components of the RAS. In derangements of pregnancy this delicate equilibrium can become unbalanced. Preeclampsia is one such case. It is a disorder of pregnancy characterized by hypertension, proteinuria and placental abnormalities associated with shallow trophoblast invasion and impaired spiral artery remodeling. Despite being a leading cause of maternal death and a major contributor to maternal and perinatal morbidity, the mechanisms responsible for the pathogenesis of preeclampsia are poorly understood. Immunological mechanisms and the RAS have been long considered to be involved in the development of preeclampsia. Numerous recent studies demonstrate the presence of the angiotensin II type I receptor agonistic autoantibody (AT1-AA). This autoantibody can induce many key features of the disorder and upregulate molecules involved in the pathogenesis of preeclampsia. Here we review the functional role of the RAS during pregnancy and the impact of AT1-AA on preeclampsia.

Topics: Angiotensin II; Animals; Autoantibodies; Calcium; Disease Models, Animal; Female; Humans; Peptidyl-Dipeptidase A; Placenta; Placenta Diseases; Plasminogen Activator Inhibitor 1; Pre-Eclampsia; Pregnancy; Reactive Oxygen Species; Renin-Angiotensin System; Thromboplastin; Vascular Endothelial Growth Factor Receptor-1

We have previously reported the presence in normal human placentae of coagulation, macrophages and helper T lymphocytes in inflammatory foci known as villitis of unestablished etiology. In order to investigate the link between coagulation and immunity, we have studied fetal stem vessel endothelium for tissue factor, which is made available by cytokines and activates coagulation via the extrinsic pathway. We found that fetal stem vessel endothelial cells of normal chorionic villi did not react with antibody to tissue factor. Normal placentae contain small numbers of villitis areas and endothelium in these areas was reactive with antibody to tissue factor. Endothelial tissue factor reactivity was more prominent in placentae from secondary recurrent spontaneous aborters and these placentae have greatly increased numbers of villitis areas. The tissue factor availability on fetal stem vessel endothelium may result from immunologically mediated cytokine release. The net effect of these reactions is the presence of lymphocytes, macrophages, coagulation, necrosis and vasculitis in villitis.

Topics: Abortion, Habitual; Chorionic Villi; Endothelium, Vascular; Female; Fetus; Humans; Inflammation; Placenta Diseases; Pregnancy; Pregnancy Trimester, Third; Thromboplastin

Topics: Adenosine Diphosphate; Adult; Antithrombins; Blood Cell Count; Blood Coagulation; Blood Coagulation Tests; Blood Platelets; Cold Temperature; Factor V; Factor VIII; Female; Fibrin; Fibrinogen; Fibrinolysis; Fibrinolytic Agents; Humans; Hypertension; Placenta; Placenta Diseases; Plasminogen; Platelet Adhesiveness; Postpartum Period; Pre-Eclampsia; Pregnancy; Pregnancy Complications, Cardiovascular; Thromboplastin

Topics: Blood Cell Count; Blood Coagulation; Blood Platelet Disorders; Female; Fibrinogen; Fibrinolysis; Humans; Infant, Newborn; Infant, Premature; Placenta; Placenta Diseases; Pregnancy; Pregnancy Complications; Thromboplastin

Topics: Abortion, Septic; Blood Coagulation Disorders; Embolism, Amniotic Fluid; Female; Fetal Death; Fibrinolysis; Gelatin; Hemorrhagic Disorders; Humans; Hydrogen-Ion Concentration; Placenta; Placenta Diseases; Plasma Substitutes; Pregnancy; Pregnancy Complications; Pulmonary Embolism; Shock, Hemorrhagic; Shock, Septic; Streptokinase; Thrombophlebitis; Thromboplastin; Thrombosis

Topics: Animals; Autopsy; Cricetinae; Eclampsia; Female; Fetal Death; Fibrin; Humans; Infant Mortality; Infant, Newborn; Kidney Glomerulus; Lung; Maternal-Fetal Exchange; Methods; Microcirculation; Placenta; Placenta Diseases; Pregnancy; Pregnancy Complications; Thromboplastin; Time Factors