title: Coagulation in vivo microcirculation and in vitro caused by endothelin-1.
abstract: This study was designed to elucidate the participation of endothelin-1(ET-1) in vivo and in vitro coagulation. The microvascular hemodynamic changes in terms of intravascular thrombus formation in rat mesentery induced by the superfusion of ET-1 (0.5, 1 and 2 pmol) were visualized by an intravital microscope system assisted by television-video tape recorder system. In addition to vasoconstriction we observed the blockade of circulation by clumps resembling thrombus in a dose dependent fashion by ET-1. Thrombus formation could be attenuated by pretreatment with superfusion of 3.8% Na citrate solution but not by the prior superfusion of 1 to 3 ng of nitroglycerine. Thrombus formation was found after the administration of 10 microliters of CaCl2 (100 nM) solution in Na citrate (3.8%, 20 microliters) and ET-1 treated field. In vitro study, a dose dependent increase in TAT (thrombin-antithrombin complexes) and decrease in AT III (antithrombin III) (%) activity, the prolongation of PT (prothrombin time) and APTT (activated partial thromboplastin time) was found by administering ET-1 immediately in native (unanticoagulated) blood in silicon coated test tubes (p < 0.05; n = 6). However in citrated blood, TAT complexes, AT III (%) activity, PT and APTT were not significantly changed after administration of the same doses of ET-1 (p > 0.05; n = 6). Therefore, this study suggested that endothelin-1 caused intravascular thrombosis and enhanced intra test tube coagulation which could be attenuated by blocking ionic calcium.
authors.affiliation: Department of Obstetrics and Gynaecology, Hamamatsu University School of Medicine, Japan.
authors.forename: A
authors.initials: A
authors.lastname: Halim
authors.forename: N
authors.initials: N
authors.lastname: Kanayama
authors.forename: E
authors.initials: E
authors.lastname: el Maradny
authors.forename: K
authors.initials: K
authors.lastname: Maehara
authors.forename: T
authors.initials: T
authors.lastname: Terao
mesh_terms: D000818:Animals; D001777:Blood Coagulation / Q000502:physiology*; D016232:Endothelins / Q000502:physiology*; D066298:In Vitro Techniques; D008833:Microcirculation / Q000502:physiology; D051381:Rats; D017208:Rats, Wistar
chemical_list: D016232:Endothelins