Tissue angiotensin I-converting enzyme activity in spontaneously hypertensive hamsters.

The purpose of this study was to measure angiotensin I-converting activity in heart, kidney, lung and cheek pouch tissue homogenates of spontaneously hypertensive and normotensive hamsters. We also determined inhibitor sensitivity and the effects of chloride anion concentration on kidney angiotensin I-converting activity in these animals. We found no significant differences in angiotensin I-converting activity between hypertensive and normotensive hamsters in all tissues tested. Inhibitor sensitivity of kidney angiotensin I-converting activity with captopril and lisonopril was similar in both groups. Finally, kidney angiotensin I-converting activity increased significantly in both groups as chloride anion concentration in the assay buffer increased. Substituting chloride anion for citrate abrogated the increase in angiotensin I-converting enzyme activity.