Enterocyte Nutrient Transport Is Preserved in a Rabbit Model of Acute Intestinal Ischemia

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Abstract
Background: The use of enteral nutrition in patients with nonocclusive splanchnic hypoperfusion is controversial. This study aims to quantitate enterocyte nutrient transport and correlate function with morphology during intestinal ischemia. Methods: New Zealand White rabbits were randomized to control (celiotomy only) 60‐minute infra‐renal aortic clamp (IRC) or 60‐minute supraceliac aortic clamp (SCC). Small intestinal brush border membrane vesicles (BBMVs) were prepared by magnesium precipitation and serial differential centrifugation. Sodium‐dependent uptake of glucose, glutamine, alanine, leucine, and arginine into BBMVs was quantitated by rapid mixing and filtration. Histologic examination of the intestine was performed by a pathologist blinded to groups. Data are reported as mean values ± SEM, with significance determined by analysis of variance at p <.05. Results: Villus heights in the IRC and SCC groups were 20% and 48% less than control, respectively. SCC histology was characterized by extensive epithelial denudation and necrosis, whereas IRC had mild focal villus edema only. Sodium‐dependent glucose and leucine transport each exhibited nonsignificant increases of 20% to 25% in the IRC group and 30% to 55% in the SCC group. No changes were noted in sodium‐dependent glutamine, alanine, and arginine uptake or sodium‐independent transport. Conclusions: Enteral nutrient transport does not correlate with mucosal architecture, is maintained during splanchnic hypoperfusion states, and likely occurs via intact crypt cells. (Journal of Parenteral and Enteral Nutrition 22:387–392, 1998)