title: Permeability of parietal pleura to liquid and proteins.
abstract: The permselectivity of the parietal pleura was determined in spontaneously breathing anesthetized rabbits and dogs. In rabbits, we injected intrapleurally 5 ml of 1-g/dl albumin solution containing 100 microCi of 131I-labeled albumin plus 100 microCi of either lactate dehydrogenase (LDH) or alpha 2-125I-macroglobulin. Dogs received 100 ml of 1-g/dl albumin solution containing 100 microCi of 131I-albumin plus 100 microCi of alpha 2-125I-macroglobulin. A transpleural pressure gradient was set, lowering the intracapsular pressure to -30 cmH2O. The solvent drag reflection coefficients (sigma f) were calculated as the ratio between tracer concentrations in capsular and pleural liquid collected at 60-180 min. In rabbits sigma f was 0.44 +/- 0.2 (SD) for albumin, 0.84 +/- 0.1 for LDH, and 0.93 +/- 0.05 for alpha 2-macroglobulin. In dogs sigma f was 0.30 +/- 0.19 for albumin and 0.53 +/- 0.15 for alpha 2-macroglobulin. The hydraulic conductivity of the parietal pleura was 2.18 +/- 1.54 microliters.h-1.cmH2O-1.cm-2 in rabbits and 1.22 +/- 1.13 microliters.h-1.cmH2O-1.cm-2 in dogs. The parietal pleura could be modeled by two pore populations with radii of 83-89 and 156-222 A. The permeability coefficient averaged 0.08-0.21 x 10(-6) cm/s for albumin, 0.06-0.09 x 10(-6) cm/s for LDH, and 0.01-0.03 x 10(-6) cm/s for alpha 2-macroglobulin.
authors.affiliation: Istituto di Fisiologia Umana, Università degli Studi di Milano, Italy.
authors.forename: D
authors.initials: D
authors.lastname: Negrini
authors.forename: D
authors.initials: D
authors.lastname: Venturoli
authors.forename: M I
authors.initials: MI
authors.lastname: Townsley
authors.forename: R K
authors.initials: RK
authors.lastname: Reed
mesh_terms: D000818:Animals; D004058:Diffusion; D004285:Dogs; D007770:L-Lactate Dehydrogenase / Q000493:pharmacokinetics*; D008208:Lymphatic System / Q000378:metabolism; D008954:Models, Biological; D010539:Permeability; D010994:Pleura / Q000378:metabolism*; D011817:Rabbits; D012709:Serum Albumin / Q000493:pharmacokinetics*; D000511:alpha-Macroglobulins / Q000493:pharmacokinetics*
chemical_list: D012709:Serum Albumin; D000511:alpha-Macroglobulins; D007770:L-Lactate Dehydrogenase