Effect of chemically defined formula diets on pancreatic mass in the rat

To establish the effect of chemically defined formula diets on pancreatic mass, 58 male Wistar rats, weighing approximately 200 g, were fed orally one of the following diets for 20 days: standard diet; partially hydrolyzed diet; elemental diet. The diets were isocaloric and provided 73 cal/day per rat. At the end of the experiment, the rats were killed and pancreas removed to assess wet weight and DNA and RNA content. Compared to the controls, the elemental diet caused a reduction in pancreatic wet weight (p less than 0.005), pancreatic DNA (p less than 0.001), and RNA content (p less than 0.001). In the group fed partially hydrolyzed diet, only pancreatic DNA content showed an highly significant reduction when compared with the reference group (p less than 0.001), whereas the value of RNA failed to reach the statistical significance. We found an increase of the ratio mg RNA/mg DNA in the partially hydrolyzed and elemental diet groups. These results suggest that long-term nutrition with the partially hydrolyzed diet, and more strongly with the elemental diet, may induce pancreatic hypoplasia.