Plasma Renin Activity: Temperature Optimum at ∼45 °C

Abstract
Renin (EC 3.4.23.15) catalyzes the proteolytic degradation of angiotensinogen to angiotensin-I. Plasma renin activity can be assessed by detection of the amount of angiotensin-I produced under well-defined incubation conditions. Despite numerous studies of incubation conditions (1)(2)(3)(4)(5)(6)(7)(8), the temperature optimum of the renin enzyme activity and the effect of the assay temperature on the reproducibility of renin activity measurement have not been reported. Here we draw attention to the temperature effect on the human plasma renin activity over the range between 30 and 50 °C.