Advertisement

Research Article Free access | 10.1172/JCI118186

Angiotensin II formation in the intact human heart. Predominance of the angiotensin-converting enzyme pathway.

L S Zisman, W T Abraham, G E Meixell, B N Vamvakias, R A Quaife, B D Lowes, R L Roden, S J Peacock, B M Groves, and M V Raynolds

Department of Medicine, University of Colorado Health Sciences Center, Denver 80262, USA.

Find articles by Zisman, L. in: PubMed | Google Scholar

Department of Medicine, University of Colorado Health Sciences Center, Denver 80262, USA.

Find articles by Abraham, W. in: PubMed | Google Scholar

Department of Medicine, University of Colorado Health Sciences Center, Denver 80262, USA.

Find articles by Meixell, G. in: PubMed | Google Scholar

Department of Medicine, University of Colorado Health Sciences Center, Denver 80262, USA.

Find articles by Vamvakias, B. in: PubMed | Google Scholar

Department of Medicine, University of Colorado Health Sciences Center, Denver 80262, USA.

Find articles by Quaife, R. in: PubMed | Google Scholar

Department of Medicine, University of Colorado Health Sciences Center, Denver 80262, USA.

Find articles by Lowes, B. in: PubMed | Google Scholar

Department of Medicine, University of Colorado Health Sciences Center, Denver 80262, USA.

Find articles by Roden, R. in: PubMed | Google Scholar

Department of Medicine, University of Colorado Health Sciences Center, Denver 80262, USA.

Find articles by Peacock, S. in: PubMed | Google Scholar

Department of Medicine, University of Colorado Health Sciences Center, Denver 80262, USA.

Find articles by Groves, B. in: PubMed | Google Scholar

Department of Medicine, University of Colorado Health Sciences Center, Denver 80262, USA.

Find articles by Raynolds, M. in: PubMed | Google Scholar

Published September 1, 1995 - More info

Published in Volume 96, Issue 3 on September 1, 1995
J Clin Invest. 1995;96(3):1490–1498. https://doi.org/10.1172/JCI118186.
© 1995 The American Society for Clinical Investigation
Published September 1, 1995 - Version history
View PDF
Abstract

It has been proposed that the contribution of myocardial tissue angiotensin converting enzyme (ACE) to angiotensin II (Ang II) formation in the human heart is low compared with non-ACE pathways. However, little is known about the actual in vivo contribution of these pathways to Ang II formation in the human heart. To examine angiotensin II formation in the intact human heart, we administered intracoronary 123I-labeled angiotensin I (Ang I) with and without intracoronary enalaprilat to orthotopic heart transplant recipients. The fractional conversion of Ang I to Ang II, calculated after separation of angiotensin peptides by HPLC, was 0.415 +/- 0.104 (n = 5, mean +/- SD). Enalaprilat reduced fractional conversion by 89%, to a value of 0.044 +/- 0.053 (n = 4, P = 0.002). In a separate study of explanted hearts, a newly developed in vitro Ang II-forming assay was used to examine cardiac tissue ACE activity independent of circulating components. ACE activity in solubilized left ventricular membrane preparations from failing hearts was 49.6 +/- 5.3 fmol 125I-Ang II formed per minute per milligram of protein (n = 8, +/- SE), and 35.9 +/- 4.8 fmol/min/mg from nonfailing human hearts (n = 7, P = 0.08). In the presence of 1 microM enalaprilat, ACE activity was reduced by 85%, to 7.3 +/- 1.4 fmol/min/mg in the failing group and to 4.6 +/- 1.3 fmol/min/mg in the nonfailing group (P < 0.001). We conclude that the predominant pathway for angiotensin II formation in the human heart is through ACE.

Images.

Browse pages

Click on an image below to see the page. View PDF of the complete article

Version history
  • Version 1 (September 1, 1995): No description
Advertisement
Advertisement