GLUTAMINE SUPPLEMENTATION DOES NOT PREVENT SMALL-BOWEL MUCOSAL ATROPHY AFTER TOTAL PARENTERAL-NUTRITION IN THE RAT

Glutamine supplementation to non-lipid parenteral nutrition has been d emonstrated to attenuate villus atrophy and increase mucosal DNA conte nt in the rat. This study was performed in order to determine the effe cts of glutamine supplementation to a balanced TPN mixture (including lipids) on epithelial cell kinetics using autoradiography. Male Spragu e-Dawley rats were used. Group 1 (control) received food and an intrav enous saline infusion. Group 2 received an intravenous TPN mixture inc luding lipids but without glutamine. The same TPN mixture, glutamine r eplacing an isonitrogenous amount of non-essential amino acids, was gi ven to Group 3. Animals were fed for 7 days, whereafter blood and inte stinal samples were taken 1 h after injection of tritiated thymidine. Microscopy of specimens from proximal jejunum revealed a significant r eduction in the number of cells in crypts and villi in both TPN groups (2 and 3) compared to orally fed animals (p < 0.001). Epithelial cell numbers were not significantly different in Group 2 and 3. Similarly, the labelling index (number of labelled cells/number of crypt cells) was not affected by glutamine administration. In plasma, glucagon conc entrations in Group 2 (TPN without glutamine) seemed to decrease compa red to Group 1 and 3 (p = 0.06). In this study, glutamine supplementat ion did not affect epithelial atrophy or cell proliferation. It is con cluded, that the effects of glutamine on mucosal atrophy and renewal i n jejunum may depend on the composition of the TPN mixture supplied du ring parenteral feeding.