Macromolecular transport in canine coronary microvasculature
Pilati, C.F.
American Journal of Physiology 258(3 Pt 2): H748-H753
1990
ISSN/ISBN: 0002-9513 PMID: 2316690 Document Number: 357154
Coronary vascular osmotic reflection coefficients (.sigma.ds) for total protein, albumin (Alb), immunoglobulin (Ig)G, and IgM were determined in the anesthetized dog. Myocardial lymph was collected from the anterior interventricular lymphatic trunk, and the .sigma.ds estimated from filtration rate-independent lymph-to-plasma protein concentration ratios (CL/Cps). Lymph flows of at least 12 times base line were needed to produce filtration rate-independent CL/Cps, and these were achieved in 9 of 12 experiments. In these nine experiments, .sigma.ds for total protein, Alb, IgG, and IgM were, respectively, 0.67 .+-. 0.02 (SE), 0.59 .+-. 0.05, 0.70 .+-. 0.03, and 0.87 .+-. 0.01. The data were fitted to a model that showed that transvascular fluid and solute flux could be described by two populations of pores. A large pore system with an equivalent radius of 235 .ANG. was responsible for 39% of the transvascular volume flow. A small pore system < 53 .ANG. accounted for the remaining flow. In a second group of experiments (n = 8), 60 min of ischemia decreased the .sigma.ds to 0.27 .+-. 0.03, 0.07 .+-. 0.05, 0.22 .+-. 0.03, and 0.69 .+-. 0.04 for total protein, Alb, IgG, and IgM, respectively. A single population of pores of 220 .ANG. could describe the entire transvascular volume flow. These results indicate that coronary vascular protein permeability is moderately high and can be increased signficantly by ischemia.