PMID- 3610941 OWN - NLM STAT- MEDLINE DCOM- 19870828 LR - 20171213 IS - 8750-7587 (Print) IS - 0161-7567 (Linking) VI - 62 IP - 6 DP - 1987 Jun TI - In-line measurement of pulmonary metabolic function in the anesthetized rabbit. PG - 2500-6 AB - Quantitative assessment of lung metabolic function is thought to provide biochemical information reflecting integrity of the pulmonary microcirculation. Although multiple indicator-dilution techniques are useful in such pharmacokinetic studies, the need for fractionation and subsequent processing of blood samples greatly prolongs data generation. Accordingly, we designed and tested an in-line system which rapidly can quantify single-pass disposition of photon-emitting substances in the pulmonary circulation of intact animals. The nuclear detection system consisted of a phoswich scintillation probe optically coupled to a photomultiplier tube. Pulses were discriminated for height and shape and counts recorded in a counter-timer, the output of which was interfaced with a personal computer. A mixture of an intravascular reference substance (99mTc-sulfur colloid) and an inhibitor of angiotensin-converting enzyme, N-[1(S)-carboxy-(4-OH-3-[125I]-phenyl) ethyl]-L-alanyl-L-proline (125I-CPAP), was injected as a bolus in the right heart of anesthetized ventilated rabbits and arterial blood was diverted through a flow-cell cuvette directly apposed to the phoswich detector. Single-pass extraction of 125I-CPAP was 39 +/- 3% (mean +/- SE; n = 20) and was depressed in a dose-dependent fashion by the addition of unlabeled CPAP (1-10 micrograms/kg) to the injection. These data indicate that we can now quantify, in the intact animal, saturable binding of an inhibitor to angiotensin-converting enzyme expressed on the surface of the pulmonary microvascular endothelium. Furthermore, such data can be obtained rapidly. FAU - Pitt, B R AU - Pitt BR FAU - Ryan, J W AU - Ryan JW FAU - Chung, A Y AU - Chung AY FAU - Woodford, M AU - Woodford M FAU - Yeates, D B AU - Yeates DB FAU - Gillis, C N AU - Gillis CN LA - eng GR - HL-13315/HL/NHLBI NIH HHS/United States GR - HL-22087/HL/NHLBI NIH HHS/United States GR - HL-32154/HL/NHLBI NIH HHS/United States GR - etc. PT - Journal Article PT - Research Support, Non-U.S. Gov't PT - Research Support, U.S. Gov't, P.H.S. PL - United States TA - J Appl Physiol (1985) JT - Journal of applied physiology (Bethesda, Md. : 1985) JID - 8502536 RN - 556Q0P6PB1 (Technetium Tc 99m Sulfur Colloid) SB - IM MH - Animals MH - Lung/*metabolism MH - Mathematics MH - Microcirculation MH - Pulmonary Circulation MH - Rabbits MH - Technetium Tc 99m Sulfur Colloid EDAT- 1987/06/01 00:00 MHDA- 1987/06/01 00:01 CRDT- 1987/06/01 00:00 PHST- 1987/06/01 00:00 [pubmed] PHST- 1987/06/01 00:01 [medline] PHST- 1987/06/01 00:00 [entrez] AID - 10.1152/jappl.1987.62.6.2500 [doi] PST - ppublish SO - J Appl Physiol (1985). 1987 Jun;62(6):2500-6. doi: 10.1152/jappl.1987.62.6.2500.