Complement-dependent hemodynamic and hematologic changes in the rabbit.
The intravenous injection of the anticomplementary protein from cobra venom, cobra factor (CoF),2 induces decreases in mean arterial blood pressure and circulating platelets in rabbits. The changes are rapidly reversed. Both changes require the presence of C3 and occur in rabbits genetically deficient in the sixth component of complement. The hypotensive effects of CoF were blocked by the histamine H2-receptor antagonist burimamide. An acute C3-dependent change in blood pressure and circulating platelets also was demonstrated following the intravenous injection of S. marcescens endotoxin. However, abrogation of these acute changes by C3 depletion did not alter the extent of a second, prolonged fall in blood pressure and platelets induced by S. marcescens endotoxin occurring after 60--90 min. C3 depletion also did not alter the lethal effects of the S. marcescens endotoxin.
D000818:Animals; D001773:Blood Cells / Q000187:drug effects / Q000276:immunology*; D001792:Blood Platelets / Q000187:drug effects; D001794:Blood Pressure / Q000187:drug effects; D002049:Burimamide / Q000494:pharmacology; D003176:Complement C3 / Q000378:metabolism; D003169:Complement Inactivator Proteins; D003165:Complement System Proteins / Q000502:physiology*; D004546:Elapid Venoms / Q000494:pharmacology; D005260:Female; D006439:Hemodynamics / Q000187:drug effects; D008070:Lipopolysaccharides / Q000494:pharmacology; D008297:Male; D010740:Phospholipases / Q000494:pharmacology; D011817:Rabbits; D012706:Serratia marcescens
D003176:Complement C3; D003169:Complement Inactivator Proteins; D004546:Elapid Venoms; D008070:Lipopolysaccharides; D003165:Complement System Proteins; D010740:Phospholipases; D002049:Burimamide