title: Hereditary C5 deficiency in man. III. Studies of hemostasis and platelet responses to zymosan.
abstract: Platelet-rich-plasma from two hemostatically normal individuals, genetically lacking the fifth component of complement (C5), failed to exhibit normal platelet aggregation, or serotonin release, in the presence of zymosan. This abnormality was found to reside in the C5D plasma rather than in the platelets as demonstrated by the inability of the deficient plasma to activate zymosan for the aggregation of washed normal platelets. The defect could be corrected by the addition of normal plasma, normal serlm, or highly purified human C5. A plasma abnormality similar to that found in the C5D individuals was also noted in plasmas deficient in C3, C6, and C7; whereas C8 plasma D behaved normally. These data suggest that this platelet reaction requires late acting C components, perhaps as the C567 complex, bound to the zymosan particles.
mesh_terms: D001792:Blood Platelets / Q000378:metabolism / Q000502:physiology; D003176:Complement C3 / Q000172:deficiency; D003182:Complement C5 / Q000172:deficiency*; D003183:Complement C6 / Q000172:deficiency; D003184:Complement C7 / Q000172:deficiency; D003185:Complement C8 / Q000172:deficiency; D003165:Complement System Proteins / Q000172:deficiency*; D004837:Epinephrine / Q000494:pharmacology; D006487:Hemostasis / Q000187:drug effects*; D006801:Humans; D010974:Platelet Aggregation / Q000187:drug effects*; D012310:Ristocetin / Q000494:pharmacology; D012701:Serotonin / Q000378:metabolism; D015054:Zymosan / Q000494:pharmacology*
chemical_list: D003176:Complement C3; D003182:Complement C5; D003183:Complement C6; D003184:Complement C7; D003185:Complement C8; D012310:Ristocetin; D012701:Serotonin; D003165:Complement System Proteins; D015054:Zymosan; D004837:Epinephrine