Comparative Studies on Factor XIII in Plasma of Various Animal Species

Factor XIII was assayed by the monodansylcadaverine incorporation method in platelet/thrombocyte-poor plasma of 14 species. In all plasmas activity was generated by thrombin. In horse, cat, goat, sheep, pig, rat, chicken, goose, and turkey values ranged from 55% to 120% of that found in human plasma. For rabbit, dog, guinea pig, and ox the values were 178%, 225%, 326%, and 471% respectively. Factor XIII activity was not correlated with fibrinogen concentration. The latter ranged from 1.37 to 4.44 mg/ml (mean: 3.31 ±0.82 mg/ml). Factor XIII of all species was neutralized to varying degrees by two human antibodies to factor XIII and, except for rabbit and the avian plasmas, by commercial rabbit antiserum to subunit A. No neutralization occurred with rabbit antiserum to subunit S, although in immunodiffusion studies a precipitin line was formed between this antiserum and plasmas of all species except rabbit and avian. Factor XIII was further characterized by gel filtration. For each species the elution properties were similar to that of human plasma factor XIII. These results indicate that there are both similarities and differences in the immunological and structural characteristics of plasms factor XIII in these mammalian and avian species.(Supported by Grant HL 14228 from the National Institutes of Health, U.S.A.)