Renin-activation by kallikrein: evidence for alkaline-activation of plasma renin

Porcine pancreatic kallikrein leads to a significant activation of human plasma renin when incubated at pH 8.2. 'Endogenous' activation of plasma renin can be seen by incubation of plasmas at the same pH. Both 'endogenous' alkaline- and kallikrein-activation of plasma renin can be inhibited by aprotinin. Both, kallikrein- and 'endogenous' alkaline activation of plasma renin are significantly correlated to cryo- and acid-activation. We suggest that kallikrein-and 'endogenous' alkaline-activiation come close to the in vivo activation process.