ACE-inhibitory activity was measured by the method of
Cushman and Cheung (1971) with slight modifications. The sample
(1 g L1; 50 mL) dissolved in 50 mmol L1 HEPESeHCl buffer containing
300 mmol L1 NaCl (pH 8.3) was mixed with 25 mL of ACE
solution (0.33 unit mL1), which was prepared by dissolving ACE in
50 mmol L1 HEPESeHCl buffer containing 300 mmol L1 NaCl