Liver regeneration in the presence of high protein and organ-containing diets.

Rats, mostly young adult males, were partially hepatectomized and administered a variety of plant, yeast and animal proteins as well as raw and cooked fresh pig organs and blood, fetal pig carcass and organs, lean beef and human term placenta over a period of 10 days. Each agent at 25% protein or in terms of 25--30% dry solids, was introduced into an aqueous mixture supplemented with salts, vitamins, corn oil and glucose. Except for a few discrepancies, liver regeneration was stimulated by most of the organ diets, the activity being similar to that of several designated controls as casein, whole blood, fibrin and wheat gluten. Egg albumin, oat flour, brain, fetal pig organs and gelatin, among others, caused depressions in regenerative activity. The proteins were also incorporated into a cellulose medium in order to study the effect of protein levels of up to 50%. The liver increment or the amount of tissue regenerated were directly related to the level of protein fed and a comparison of the effects of casein and its hydrolysate prepared enzymatically, revealed that the action of the various diets is directly related to the amino acid contents or to the protein equivalence, the essential amino acids being present. No unique role could be ascribed to the stimulatory action of raw and cooked liver as compared to the other organs investigated in the same series. The wet and dry liver to total body weight ratios for intact rats fed the present diets over the same period correlated with the increment findings for the operated animals to a moderate degree.