Proteolytic Enzymes. HI. Circulating Esterase Activities after Parenteral Trypsin and Chymotrypsin in Rabbits.

The effect of urokinase and fibrinolytic euglobulins on synthetic amino acid esters

“…The lack of increase in esterase activity on the addition of urokinase to plasma possibly might be due to the well-known presence of plasmatic inhibitors (Bastian, Hill & Ercoli, 1956). The decrease in activity on the addition of urokinase together with streptokinase compared with that obtained on the addition of streptokinase alone could be explained either by a competitive effect of the urokinase (which is added to the plasma before streptokinase) on plasminogen to make it no longer available for streptokinase activation, or by the presence of an inhibitory substance for esterase activity of plasmin in the urokinase preparation.…”

“…When fibrinolytic euglobulins are added to plasma, the lack of increase of esterase activity could be caused by the inhibitors of the plasma which have been shown to inhibit ester-splitting activity of trypsin (Bastian et al 1956). The significant inhibition ofthe plasma-esterase activity by the non-fibrinolytic euglobulins could be due to the presence in the euglobulins of inhibitors which might have been eliminated from the fibrinolytic euglobulins during their preparation.…”

Interrelationship of Human Plasma Kallikrein and Plasmin in Inflammation

“…Following intravenous administration of streptokinase to rabbits, increased levels of fibrino lytic activity could readily be detected, so that all effective antiedema concentrations of streptokinase produced a demonstrable fibrino lytic response in the rabbit [134], However, no fibrinolysis was noted after intramuscular administration of streptokinase in humans [135], nor could trypsin or chymotrypsin be detected in plasma of rabbits following intramuscular administration of the proteinases in doses as 7.5 mg/kg [136], Nevertheless, as pointed out by others [132], the method used to detect the small quantities of enzyme released in vivo may not have been sensitive enough or the time of sampling may not have been correctly chosen. Specific inhibitors of plasmin such as e-aminocaproic acid should be tested for blocking the antiphlogistic action of streptokinase and plasmin.…”

Proteolytic enzymes: a therapeutic evaluation

“…Here too, as with trypsin, increased enzyme activity in the circulation cannot be demonstrated. 80 In the case of streptokinase, it is more difficult to make comparisons. Several of the reports refer to the streptokinase dosage in animals in milligrams per kilogram, a term which has little meaning since pl'eparations can vary greatly in their activity depending upon their state of purity.…”