title: Trypsin activation of inactive renin in human plasma. An assessment of some methodological aspects.
abstract: 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 degrees 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 degrees C while an additional 40% is lost during the incubation at 37 degrees C if no SBTI is added.
mesh_terms: D004789:Enzyme Activation / Q000187:drug effects*; D006801:Humans; D012083:Renin / Q000097:blood*; D013997:Time Factors; D014357:Trypsin / Q000494:pharmacology*; D014361:Trypsin Inhibitors / Q000494:pharmacology
chemical_list: D014361:Trypsin Inhibitors; D014357:Trypsin; D012083:Renin