Renal vascular resistance changes following thrombin-induced intravascular coagulation: role of platelet and fibrin emboli.
The renal vasculature in the dog reacts to thrombin-induced intravascular coagulation with increasedd resistance. A constant rate infusion of 75 NIHu thrombin/kg b.w. reduced renal blood flow by approximately 55% in 30 min. Renal blood flow had almost regained preinfusion values within 30 min after the end of the infusion. Marked reduction in renal blood flow was not associated with increment of renal regional radioactivity in dogs pretreated with Cr-51 labeled platelets. The renal a-v difference in platelet counts did not contrast with other regions subjected to identical doses of thrombin. It is therefore unlikely that the flow changes are caused by vascular blockage by platelets. The flow decrease was accompanied by increase renal radioactivity in dogs pretreated with I-125 fibrinogen. This may imply renal accumulation of fibrin with obstruction to flow. Substantial renal blood flow reduction occurred with no or insignificant consumption of fibrinogen or changes in renal radioactivity after defibrinogenation. It is concluded that thrombin also induces a humoral vasoconstriction in the kidney.
D000818:Animals; D001772:Blood Cell Count; D001777:Blood Coagulation / Q000187:drug effects*; D001792:Blood Platelets / Q000502:physiology*; D001794:Blood Pressure / Q000187:drug effects; D003864:Depression, Chemical; D004211:Disseminated Intravascular Coagulation / Q000139:chemically induced / Q000503:physiopathology; D004285:Dogs; D005260:Female; D005337:Fibrin / Q000502:physiology*; D005340:Fibrinogen / Q000378:metabolism / Q000494:pharmacology; D007668:Kidney / Q000098:blood supply / Q000378:metabolism; D008297:Male; D012039:Regional Blood Flow / Q000187:drug effects; D013268:Stimulation, Chemical; D013917:Thrombin / Q000008:administration & dosage*; D014655:Vascular Resistance / Q000187:drug effects*
D005337:Fibrin; D005340:Fibrinogen; D013917:Thrombin