抄録
To clarify the interaction between F. VIII and thrombin, coagulation studies and affinity chromatographies were accomplished.
Incubation of normal plasma or purified F. VIII with thrombin (0.01-1.0U/ml f. c.) resulted in an marked increase and then in rapid decrease in VIII: C. Re-addition of the same dose of thrombin into the exhausted normal plasma or purified F. VIII failed to reincrease VIII: C, accordant to the fact that VIII: C in some of DIC cases did no longer increase by addition in vitro of thrombin.
When purified F. VIII preparation was applied on thrombin- (or Xa-) Sepharose column, approximately one half of F. VIII complex was washed out by starting buffer with the protein front, and the eluting buffer (0.3M in NaCl) also produced the rest F. VIII complex (VIII: C, VIIIR: AG and VIIIR: WF) altogether. The eluting F. VIII was not or less activated by additional trace of thrombin and was more labile as compared to native F. VIII. Its electrophoretic mobility remained unchanged on crossed immunoelectrophoresis.
Conclusively, the results seemed to be an additional evidence of the interaction or activation of F. VIII by thrombin (and/or by Xa) and to explain the discrepancy between one-stage and two-stage VIII: C in some DIC cases.
