Processing of Angiotensin and Other Peptides by the Lungs

Abstract

The sections in this article are: Historical Background Pulmonary Metabolism Angiotensin I Bradykinin Angiotensin II Angiotensin III Angiotensin‐Converting Enzyme: Kininase II Cellular and Subcellular Sites of Relevant Pulmonary Enzymes Immunocytochemistry Pulmonary Endothelial Cells as a Model System Clinical Implications Actions of Peptide Hormones on Lungs Other Peptides Discussion and Future Directionsa

Integrating in vitro organ-specific function with the microcirculation

“…Pulmonary endothelial cells comprise one of three thin layers that comprise the alveolar membrane, and have important metabolic functions related to the processing of vasoactive substances. For example, angiotensin converting enzyme (ACE) is expressed uniquely on the surface of the pulmonary endothelium and not only converts angiotensin I to angiotensin II, it also inactivates bradykinin [28]. In addition, the pulmonary endothelium is actively antithrombogenic, primarily through its ability to secrete prostacyclin and express ADPases [29-32].…”

Assay and computation of angiotensin-converting enzyme activity of endothelial cells

“…Angiotensin I is converted to angiotensin II and bradykinin is inactivated during a single passage through the pulmonary" vascular bed [for refs see (4)]. We now know that the same enzyme (EC 3.4.15.1), known both as angiotensin-converting enzyme (ACE) and as kininase II, is responsible for the formation of angiotensin II (a substance that tends to raise blood pressure) and for the degradation of bradykinin (a substance that tends to lower blood pressure).…”