title: Effect of temperature on alveolar liquid and protein clearance in an in situ perfused goat lung.
abstract: To study the mechanisms of alveolar liquid and protein clearance, we investigated the effect of four different temperatures (7, 18, 30, and 38 degrees C) on the rate of liquid, [14C]mannitol, and 125I-labeled albumin (125I-albumin) transport from the air spaces of isolated perfused in situ goat lungs over 4 h under isogravimetric conditions. The concentrations of both native proteins and 125I-albumin in the alveolar fluid after 4 h were used to estimate alveolar liquid clearance. We instilled autologous serum (2 ml/kg) with 125I-albumin and [14C]mannitol into the distal air spaces of one lung and 131I-labeled albumin into the perfusate to measure the capillary-to-alveolar permeability to protein. Alveolar liquid clearance progressively declined from a control value of 24 +/- 6% at 38 degrees C to 12 +/- 7% at 30 degrees C, to 3 +/- 3% at 18 degrees C, and to -15 +/- 11% at 7 degrees C. 125I-albumin clearance into the perfusate was 0.3%/h of the instilled 125I-albumin at 38 degrees C. The clearance decreased abruptly to 0.06%/h at 30 degrees C and then slightly increased to 0.08%/h at 18 degrees C and to 0.15%/h at 7 degrees C. There were no changes in transport except for a twofold increase in mannitol at 7 degrees C. Increased permeability of the alveolar barrier to protein and small-molecular-weight tracers at 7 degrees C indicates that the barrier function of the alveolar epithelium is disrupted at this low temperature.(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Department of Medicine, University of California, San Francisco 94143-0130.
authors.forename: V B
authors.initials: VB
authors.lastname: Serikov
authors.forename: M
authors.initials: M
authors.lastname: Grady
authors.forename: M A
authors.initials: MA
authors.lastname: Matthay
mesh_terms: D000818:Animals; D001794:Blood Pressure / Q000502:physiology; D001826:Body Fluids / Q000378:metabolism*; D006041:Goats; D006400:Hematocrit; D008168:Lung / Q000378:metabolism*; D008353:Mannitol / Q000493:pharmacokinetics; D009929:Organ Size / Q000502:physiology; D010477:Perfusion; D010539:Permeability; D011506:Proteins / Q000378:metabolism*; D011650:Pulmonary Alveoli / Q000378:metabolism*; D011652:Pulmonary Circulation / Q000502:physiology; D012711:Serum Albumin, Radio-Iodinated; D013696:Temperature
chemical_list: D011506:Proteins; D012711:Serum Albumin, Radio-Iodinated; D008353:Mannitol