IMMUNOCHEMICAL COMPARISON OF ANGIOTENSIN-1 CONVERTING ENZYMES FROM DIFFERENT RAT ORGANS

1. 1. Catalytic activity of angiotensin 1 converting enzyme from rat lung, serum, kidney, brain, testis, or epididymis was similarly inhibited by specific rabbit antisera to purified rat lung angiotensin 1 converting enzyme. 2. 2. However, on radioimmunoassay, the enzymes from testis and epididymis were considerably less potent inhibitors of radioimmune binding than those from lung, serum, brain, spleen and kidney. 3. 3. Ouchterlony diffusion studies with the antisera revealed a second precipitin band in extracts of testis and epididymis that exhibited partial identity with angiotensin 1 converting enzyme of lung. 4. 4. These data indicate the presence of at least two immunologically cross-reacting angiotensin 1 converting enzymes in the rat. © 1979.