Plasma fibronectin response to sepsis: mobilization or synthesis?

Plasma fibronectin (PFN) is a high molecular weight adhesive glycoprotein. Following trauma or sepsis PFN is acutely depleted, with rapid restoration of normal or supranormal levels after 24 to 48 hours. Cecal ligation with perforation provides an animal model of surgical trauma combined with polymicrobial sepsis. The present study examines whether this PFN level restoration 6 to 24 hours postoperatively is associated with de novo PFN synthesis and how this response is altered by pre-existing protein-calorie deprivation. Thirty-six adult male rats were divided into four groups: I--Controls, II--Prefasted Controls, III--Ligated, IV--Prefasted and Ligated. Control and experimental groups received intracardiac 35S-methionine 2 hours postoperatively. Plasma fibronectin (PFN) levels, PFN specific activity, plasma total protein, and total protein specific activity were determined at 0, 6, 24, and 48 hours postoperatively. Ligated rats (Groups III & IV) demonstrated significant PFN level increases 24 to 48 hours postoperatively (p less than 0.01-0.05). Despite a significant preoperative PFN level depression in prefasted rats (Groups II & IV), the 24-48 hours response to cecal ligation was not significantly altered. PFN specific activity was significantly increased among the operative groups 6 hours postoperatively, demonstrating de novo PFN synthesis following cecal ligation and perforation.