Metabolic and pharmacokinetic activity of the isolated sheep bronchial circulation

RYAN. Metabolic and pharmacokinetic activity of the isolated sheep bronchial circulation. J. Appl. Physiol. 67(3): 1041-1047, 1989.-We sought to determine bronchial vascular metabolic and pharmacokinetic activity toward benzoyl-Phe-Ala-Pro (BPAP), ADP, adenosine, and prostaglandin EP (PGE & by developing an isolated sheep bronchial circulation preparation. We measured mean transit time (t), uptake, and metabolism by injecting 3H-labeled substrates with [14C]sucrose into the bronchial artery of sheep lungs stripped clean of parenchymal tissue. After [3H]BPAP the t for 3H was the same as for 14C. Thirty-six percent of the injected BPAP was converted to metabolite ( [3H]benzoyl-Phe) in a single pass. An inhibitor of angiotensin-converting enzyme, SQ 20,881, depressed BPAP metabolism by 50%) while perfusion of the bronchial circulation with glutaraldehyde reduced metabolism to a basal level. Afte