Delayed elevation of ED1-cellular fibronectin in plasma following postsurgical bacteremia.
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)
Rizk
T A
TA
Department of Physiology and Cell Biology, Albany Medical College of Union University, New York 12208.
Rebres
R A
RA
Vincent
P A
PA
Charash
W E
WE
McKeown-Longo
P J
PJ
Lewis
E P
EP
Brien
T P
TP
Minnear
F L
FL
Fortune
J B
JB
Saba
T M
TM
D000818:Animals; D016470:Bacteremia / Q000097:blood*; D002199:Capillary Permeability; D004730:Endothelium, Vascular / Q000378:metabolism; D005109:Extracellular Matrix / Q000378:metabolism*; D005353:Fibronectins / Q000097:blood* / Q000737:chemistry* / Q000378:metabolism; D008168:Lung / Q000378:metabolism; D008196:Lymph / Q000378:metabolism; D011183:Postoperative Complications; D011506:Proteins / Q000378:metabolism; D011652:Pulmonary Circulation; D012756:Sheep
D005353:Fibronectins; D011506:Proteins