Date of Award:


Document Type:


Degree Name:

Master of Science (MS)


Nutrition, Dietetics, and Food Sciences

Department name when degree awarded

Nutrition and Biochemistry

Committee Chair(s)

Deloy G. Hendricks


Deloy G. Hendricks


Ethelwyn B. Wilcox


Thomas M. Farley


A study of the adaptive changes of some enzyme activities to the dietary protein intake was made in the liver, kidney, and pancreas of rats and serum of humans.

The rats fed the 40 per cent casein diet had a higher rate of weight gain and the weights of the liver and kidney were higher than in the rats fed the 10 per cent casein diet.

Three enzymes involved in the elimination of excess nitrogen from the body were found to show a similar response to increased dietary protein intake. These enzymes were: D-amino acid oxidase in the kidneys, arginase in the liver and kidneys, and glutamic-pyruvic transaminase in the liver of rats. The rate of enzyme induction was detectable the second day, being high during the first four days and reaching the maximum value on the fourth day. Thereafter, the enzymatic activity did not change much.

The alkaline phosphatase activities in the liver and kidneys of the rats did not show significant change during consumption of the diets containing 10 per cent or 40 per cent casein. Samples of pancreatic trypsinogen and chymotrypsinogen of the rats were not collected during the appropriate time to note any significant changes caused by the diets. A more appropriate experimental design, including proper timing for feedings and dissections, for the study of the adaptation of the proteolytic enzymes in the pancreas of the rats is desirable and recommended. The values for the circulating enzymes of the human serum, 0-amino acid oxidase, glutamic-pyruvic transaminase, and alkaline phosphatase were not found to be affected significantly by the diets containing 12 per cent and 30 per cent protein calories.