AJP - Lung Cellular and Molecular Physiology, Vol 266, Issue 6 689-L697, Copyright © 1994 by American Physiological Society
Delayed elevation of ED1-cellular fibronectin in plasma following postsurgical bacteremia
T. A. Rizk, R. A. Rebres, P. A. Vincent, W. E. Charash, P. J. McKeown-Longo, E. P. Lewis, T. P. Brien, F. L. Minnear, J. B. Fortune and T. M. Saba
Department of Physiology and Cell Biology, Albany Medical College of Union University, New York 12208.
Fibronectin (Fn) exists in both a soluble form in plasma and lymph as well
as an insoluble form in the extracellular matrix. Matrix-localized cellular
fibronectin (cFn) contains extra domains (ED1 and/or ED2) not found in
plasma Fn (pFn). Very little (< 1-2%) ED1-containing cFn exists in
normal blood, and its rapid release into plasma and/or lymph is believed to
reflect acute vascular injury. We used a polyclonal antibody to sheep pFn
and a monoclonal antibody to ED1 domain of cFn to measure both pFn and
ED1-cFn in relationship to lung lymph flow (QL), lung lymph-to-plasma (L/P)
total protein concentration ratio, and lung protein clearance (LPC).
Unanesthetized sheep (n = 7) were injected intravenously with Pseudomonas
aeruginosa (5 x 10(8)) at both 2 and 7 days following surgical preparation
of a lung lymph fistula. After both bacterial challenges, we observed an
early increase in QL and a small decline in the L/P ratio (0-2 h),
reflecting increased fluid filtration in the presence of an intact vascular
barrier. This was followed by a further increase (P < 0.05) in QL; an
elevation in the L/P ratio; and a marked (P < 0.05) increase in LPC over
3-6 h, indicative of an increase in lung endothelial protein permeability.
Before the first bacterial infusion, ED1-cFn in plasma was 9.97
micrograms/ml or approximately 2% of the total Fn antigen in plasma;
whereas ED1-cFn in lung lymph was 6-8% of total lymph Fn.(ABSTRACT
TRUNCATED AT 250 WORDS)
