Effects of enteral vs parenteral nutrition on reticuloendothelial function

Previous investigations have shown that animals maintained with enteral nutrition are better able to survive an intraperitoneal bacterial challenge than animals receiving parenteral nutrition. The aim of this study was to assess the effects of enteral and parenteral nutrition on reticuloendothelial function. Eighteen enteral-fed male Sprague-Dawley rats had access to a standard hyperalimentation solution via a sipper tube ad libitum. Seventeen parenteral-fed animals received the same solution at an infusion rate determined by the volume ingested by the pair-fed enteral animals. All animals had central venous catheters. After 12 days, reticuloendothelial function was assessed by measuring the clearance rate (K) and the organ distribution of intravenous 51Cr-labeled sheep red blood cells and by plasma fibronectin levels. Nutritional status was assessed by body weight and nitrogen balance. K values in enteral and parenteral animals were similar (0.110 +/- 0.011 and 0.140 +/- 0.012, respectively, mean +/- SEM) as were plasma fibronectin levels (196 +/- 22 and 228 +/- 15 micrograms, respectively). Organ distribution of the 51Cr-labeled sheep red blood cells was the same in both groups. Nitrogen balance and body weights were also similar in both groups. These data demonstrate that in this experimental model enteral nutrition and parenteral nutrition were equally effective at maintaining reticuloendothelial function and nutritional status.