Dependence of renal ACE2 activity on substrate concentration in the MF1 mouse. Effect of substrate concentration on the time course of product formation in (A) male and (B) female mice. Data are representative of three experiments performed in triplicate. (C) Effect of substrate concentration on product formation at 40 min in male and female mice. Also shown is the determination of K
m and V
max; *P < 0.001 versus female by t-test; n = 4-5/group. Two-way ANOVA revealed a significant effect of substrate (P < 0.0001) and sex (P < 0.0001) on renal ACE2 activity.