ENTEROCYTE NUTRIENT TRANSPORT IS PRESERVED IN A RABBIT MODEL OF ACUTEINTESTINAL ISCHEMIA

Background: The use of enteral nutrition in patients with nonocclusive splanchnic hypoperfusion is controversial. This study aims to quantit ate enterocyte nutrient transport and correlate function with morpholo gy during intestinal ischemia. Methods: New Zealand White rabbits were randomized to control (celiotomy only) 60-minute infrarenal aortic cl amp (IRC) or 60-minute supraceliac aortic clamp (SCC). Small intestina l brush border membrane vesicles (BBMVs) were prepared by magnesium pr ecipitation and serial differential centrifugation. Sodium-dependent u ptake of glucose, glutamine, alanine, leucine, and arginine into BBMVs was quantitated by rapid mixing and filtration. Histologic examinatio n of the intestine was performed by a pathologist blinded to groups. D ata 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 h istology was characterized by extensive epithelial denudation and necr osis, whereas IRC had mild focal villus edema only. Sodium-dependent g lucose and leucine transport each exhibited nonsignificant increases o f 20% to 25% in the IRC group and 30% to 55% in the SCC group. No chan ges were noted in sodium-dependent glutamine, alanine, and arginine up take or sodium-independent transport. Conclusions: Enteral nutrient tr ansport does not correlate with mucosal architecture, is maintained du ring splanchnic hypoperfusion states, and likely occurs via intact cry pt cells.