The Dipeptide Alanyl-Glutamine Prevents Intestinal Mucosal Atrophy in Parenterally Fed Rats

Alanyl glutamine-enriched total parenteral nutrition restores intestinal adaptation after either proximal or distal massive resection in rats

This study was designed to determine whether alanyl glutamine-containing total parental nutrition (TPN) can restore the impaired adaptive process of the remaining intestine, observed with administration of conventional TPN, after massive small-bowel resection. Seventy-four male Sprague-Dawley rats weighing 250 g were randomly divided into seven groups. Group I rats (n = 10) were killed after overnight fasting. Group II animals (n = 32) underwent massive small bowel resection (85%) with preservation of the first 15 cm of jejunum. Group III animals (n = 32) were also submitted to massive small-bowel resection with preservation of 15 cm of terminal ileum. Three different TPN solutions were prepared. Solution A was a conventional formulation that did not contain glutamine. Solution B contained 1.88 times the amino acid concentration of solution A. Solution C was prepared by adding alanyl glutamine (2 g/100 mL) to solution A. Solutions B and C were isonitrogenous and isocaloric. Each solution was infused to groups II and III, which were subdivided into groups IIA (n = 10), IIB (n = 11), IIC (n = 11), IIIA (n = 10), IIIB (n = 11), and IIIC (n = 11). After 1 week of TPN (270 kcal/kg per day), the experimental animals were killed and the intestine was taken for examination. Final body weight did not differ significantly among the groups, and there was no difference in nitrogen balance among the animals that received solution B or C.(ABSTRACT TRUNCATED AT 250 WORDS)

Zinc-deficient diet impairs adaptive changes in the remaining intestine after massive small bowel resection in the rat

An investigation was conducted on the influence of the presence of zinc in an elemental diet on the mucosa of residual intestine after massive small bowel resection. A total of 34 male Sprague-Dawley rats were divided into five groups: control animals (n = 10) were killed after overnight fasting; a second group (n = 14) underwent massive small bowel resection preserving 10 cm of terminal ileum, and the third group (n = 10) underwent sham operation. Animals in the second and third groups were fed either a commercially available elemental diet or a zinc-deficient diet for 2 weeks; they were then killed. In animals receiving the zinc-deficient diet, a significant decrease (P < 0.05) was noted in plasma zinc and total protein, and in mucosal wet weight (duodenum), thickness (duodenum and ileum), and protein (duodenum) and DNA (duodenum) content. Mucosal sucrase and maltase specific activities in the duodenum and ileum fell but diamine oxidase levels did not. These results suggest that zinc plays an important role in intestinal adaptation in the rat, and indicate that this trace element is essential for intestinal mucosal preservation in this animal.