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Biomedical subjects

S J Dudrick

Publications and source records attributed to S J Dudrick.

At least 145 records · Page 8Linked to original sources

Structural and hormonal alterations in the gastrointestinal tract of parenterally fed rats.

This study examines the effect of prolonged absence of oral food intake on structural parameters of the gastrointestinal tract in rats maintained nutritionally by intravenous feeding for up to 3 weeks. During this time, their body weights increased by 22%. Controls fed a nearly isocaloric oral diet were sham operated and harnessed in the same manner as their parenterally fed counterparts. Parenteral feeding resulted in a significant decrease in the weights (per 100 g body weight) of the oxyntic gland area of the stomach, small intestine, and pancreas. The weights of the spleen, testes, kidneys, and antral region of the stomach were unaltered. In the small intestine there was a significant loss of DNA and a near doubling of the RNA:DNA ratio in the parenterally fed animals. In the absence of an oral diet antral gastrin levels decreased to one-thirtieth of the control level. The following conclusions are suggested by these results. First, the oral intake and/or physical presence of food within the gastrointestinal tract are necessary for structural maintenance of some tissues of that tract. Second, the disproportionate decrease in weight that occurs in certain tissues is apparently unrelated to the absence of nutrients which might normally be utilized directly from the lumen. Third, maintenance of normal tissue stores of the hormone, gastrin, is dependent on stimuli provided by oral ingestion and the presence of food in the gastrointestinal tract.

Animals↗

Action of gastrin on gastrointestinal structure and function.

In previous communications we have reported using the rat fed by total parenteral nutrition to examine the effects of the absence of food from the gut on functional and structural parameters of the gastrointestinal tract. In the current study three groups of animals were fed parenterally; one received a continuous infusion of pentagastrin equal to about one-half the D50 for acid secretion, another received a comparable infusion of histamine, and a third group was given only the liquid diet. These animals were compared to orally fed sham operated controls. The parenterally fed animals had significantly lower levels of antral and serum gastrin. When compared to whole body weight, the weights of the oxyntic gland area of the stomach, the pancreas, and the small intestine were significantly lower. In addition, the total and specific activities of the disaccharidase enzymes were significantly reduced. Pentagastrin prevented both the decreases in weights of the gastrointestinal tissues and the decreases in dissaccharidase activity. Histamine was without effect. We conclude that pentagastrin prevents the changes in gastrointestinal structure and function caused by the absence of food from the gut and that the trophic action of gastrin is necessary for the maintenance of the functional and structural integrity of the gastrointestinal tract.

Animals↗

Postoperative oral and intravenous nutrition.

Oral and intravenous high calorie-amino acid nutritional therapy postoperatively resulted in significant weight gain, improved colonic wound healing and maintenance of normal intravascular albumin levels. Provision of caloric needs without amino acids minimized weight loss postoperatively. However, infusion of hypertonic dextrose solutions resulted in severe generalized hepatic fatty infiltration and marked hypoalbuminemia. Protein and calorie deprivation by administration of 5% dextrose and water resulted in the greatest postoperative weight loss, reduced intravascular albumin levels and decreased colonic anastomotic strength. Comparison of oral and intravenous diet administration demonstrated that hypertonic dextrose infusion was markedly deleterious to hepatic morphology and serum protein metabolism in normal rats. Further clinical investigation appears indicated in previously well-nourished patients undergoing extensive surgery who will not be able to ingest adequate nutrients in the postoperative period.

Administration, Oral↗