EFFECT OF PROTEIN DEFICIENCY AND CHOLESTEROL FEEDING ON THE LIVER OF DOGS

Abstract

Fatty livers were produced in dogs maintained on a 33% fat protein-deficient diet for 10-16 wks. There was no fatty infiltration at the end of the 1st wk., but added cholesterol caused a uniformly higher total lipid and cholesterol content of the liver within that time; more of the cholesterol was in the free form than normally. Fatty infiltration of the liver was prevented for 16 wks. in dogs on a high fat diet by 2 g. of casein/lb. body wt. daily, but this protein intake did not prevent "cholesterol" fatty livers. Protein depletion impairs hepatic dye clearance and causes elevation of serum phosphatase in dogs. Adding cholesterol to the high-fat protein-deficient diet produced an abrupt drop in dye clearance at the beginning of the expt., and a uniformly higher elevation of serum phosphatase than that caused by simple protein deficiency. There was generally an inverse relationship between serum phosphatase and Rose Bengal clearance, but initially the drop in dye clearance was disproportionately sharp. Irrespective of diet or duration of the expt., all the dogs with increased liver lipids or cholesterol had a reduced dye clearance, but the degree of impairment was not necessarily proportional to the fattiness or cholesterol content of the liver. Enlargement of the fatty liver was largely or entirely accounted for, according to calculations, by the increase in lipids.