Plasma fibronectin response to Escherichia coli and hemoglobin

T. S. Velky, F. Kagawa, A. G. Greenburg and J. C. Yang

Low levels of plasma fibronectin (PFN), an adhesive glycoprotein postulated to augment reticuloendothelial function, can predispose animals to a poor clinical outcome following sepsis. In the present study, the PFN levels of adult male rats were measured prior to injection of intraperitoneal Escherichia coli and/or stroma-free hemoglobin (SFH) and subsequently at 4, 24, and 48 hours. Intraperitoneal E coli alone elicited insignificant PFN level depression at four hours, with significantly elevated levels only in the high-dose group at 24 (P less than .05) and 48 hours (P less than .01). Intraperitoneal SFH alone did not alter PFN levels from baseline values; when combined with E coli significant four-hour level depression is noted (P less than .05). Elevation of PFN levels by 24 hours occurs in a dose-dependent fashion, returning to baseline values 48 hours postinoculation. Significant mortality was observed only with high doses of E coli combined with SFH. The PFN levels are elevated 24 to 48 hours following high-dose E coli injection. Stroma-free hemoglobin alone has no effect, but when combined with E coli results in PFN level depression four hours postinoculation, contributing to impairment of systemic host defenses and possibly predisposing to greater mortality.