Absence of synergism between tissue-type plasminogen activator and urokinase on plasminogen activation rate in plasma

Effects of tissue-type plasminogen activator (t-PA), urokinase(u-PA) and their combinations on plasminogen activation rate (PAR) in plasma, were investigated. T-PA and u-PA over concentrations range of 10 U/ml to 50 U/ml induced a linear, concentration dependent increase in PAR. Combinations of t-PA and u-PA in ratios of 3/1,1/1 and 1/3 induced additive but not synergistic effect in the activation of plasminogen. We conclude, therefore, that t-PA and u-PA do not act synergistically in the activation of plasminogen in plasma .