Mechanism of action of renalase. A, Effect of hRenalase1 on plasma epinephrine. Buffer (Control) or 1.5 mg/kg of recombinant renalase (hRenalase1) was administered by a single subcutaneous injection to knockout mice at 8 wk of age, and plasma epinephrine concentrations were measured 24 h later in both groups by HPLC. n=8 for each group. Control compared to hRenalase1 with the Mann‐Whitney test. *P<0.05. B, Correlation between the catalytic efficiency of hRenalase1 and the cysteine to alanine mutants and their effect on BP. Line indicates linear regression; r, correlation coefficient. C, Correlation between the catalytic efficiency of hRenalase1 and the cysteine to alanine mutants and their effect on heart rate. HR indicates heart rate; bpm, beats per minute; line, linear regression; and r, Spearman correlation coefficient. D, Acute effect of WT and C47A on BP. Arrow indicates intravenous injection of buffer (control) or 1 mg/kg of hRenalase1, or 1 mg/kg C47a mutant in anesthetized mice; representative experiment.