Immunological comparison between humanandrat plasminogen activators inbloodandthevessel wall

SUMMARY Toevaluate theratasanexperimental modelforplasminogen activator research, the ability ofantibodies specific forhumantissue typeplasminogen activator andurokinase tosuppresstheplasminogen activator activity inwholeplasma andinthevessel wall was studied inboth ratandman. Plasminogen activator activity inplasma was assayed on fibrin plates containing plasminogen. Plasminogen activator inthevessel wall was shownbythefibrin slide techniqde. Antibodies against humantissue typemelanoma cell activator andurokinase were raised ingoats andmixedintothefibrin film orthefibrin plates. Inbothspecies antibodies'-to melanoma cell activator were able tosuppresstheplasminogen activator activity completely inplasma andinthe vessel wall. Anti-urokinase, however, hadno suppressing effect. Inratplasmatheinhibitory effect on thefibrinolytic activity was seenonlywithhighconcentrations ofantibodies against melanoma cell activator, whichsuggests that ratplasminogen activator inplasma andvessel walls issimilar- to,butnotidentical with, humantissue typeplasminogen activator. Plasminogen activators a- specific proteolytic enzymes.-which'