The following methodological aspects of the use of trypsin as activator of inactive renin in human plasma have been studied:a) the effect of SBTI on renin activity and angiotensin;b) the reaction velocity of trypsin on inactive renin;c) the optimum trypsin concentration;d) the ability of human plasma to neutralize exogenous trypsin. Our results show that:1) Some commercially available SBTI may exert an angiotensinase-like effect which can be abolished by PMSF. 2) At 4°C activation of inactive renin reached a maximum within the first two minutes then no further activation could be demonstrated. 3)Trypsin 2 mg/ml yielded more inactive renin than trypsin 1 or 0.5 mg/ml. A higher concentration (3 mg/ml) gave substantially equivalent activation as(with)trypsin 2 mg/ml whereas when using a still higher concentration (4 mg/ml)a degradation of the renin system components could be noted. 4)Endogenous trypsin inhibitors can eventually inactivate exogenous trypsin up to 3 mg/ml. About 20 % of renin is destroyed by trypsin 4 mg/ml within 2 min at 4°C while an additional 40% is lost during the incubation at 37°C if no SBTI is added.
ASJC Scopus subject areas
- Internal Medicine