THE EFFECT OF ENTERAL GLUTAMINE DEPRIVATION AND SUPPLEMENTATION ON THE STRUCTURE OF RAT SMALL-INTESTINE MUCOSA DURING A SYSTEMIC INJURY RESPONSE

Background: An aseptic model of tissue injury (the induction of absces ses by subcutaneous injections of turpentine) was used to examine the proposal that changes in glutamine metabolism lead to structural damag e in the epithelium of the small intestine during the systemic respons e to injury and to investigate the role of dietary glutamine in the ma intenance of mucosal structure in the small intestine of control and i njured rats. Methods: Glutamine-free and glutamine-rich (3.6% glutamin e by weight) diets were fed to rats before and during an acute-phase r esponse to injury. Pair-fed groups of animals enabled an independent a ssessment to be made of the effects of the associated dietary restrict ion on the mucosal epithelium. Results: Adaptive increases in villus h eight and crypt depth were seen in response to 4 days of feeding of th e glutamine diet. Pair-feeding (30% dietary restriction) of either die t induced mucosal atrophy (loss of wet weight and nitrogen) without ch anges in villus height or crypt depth in the proximal tercile of the s mall intestine. Systemic injury, however, had no effect on the weight or nitrogen content of the mucosa (relative to pair-feeding). Gross hi stologic appearance, villus height, and crypt depth were also unchange d by the response to injury. Conclusions: The study provided no eviden ce to support the proposal that alterations in the availability of die tary glutamine during systemic injury (induced by turpentine injection s) lead to structural damage to the epithelium.