Origin of hypercholesterolemia in chronic experimental nephrotic syndrome

Sixteen nephrotized rats and eight controls were submitted to a continuous sterol balance for two weeks. During the whole experiment (two months) the rats were pair-fed a balanced sterol-free diet and their proteinuria regularly measured as a parameter of the nephrotic state. Serum cholesterol and albumin were also measured at the end of the experiment. Liver and carcass (excluding intestine and central nervous system) as well as feces were submitted to sterol analysis by gas-liquid chromatography. Sterol losses were corrected for by adding radioactive cholesterol and cholic acid at the beginning of the methodological procedures. The results showed that while fecal sterol excretion was similar in the nephrotic group as compared to controls, a definite increase in serum, carcass, and liver cholesterol was observed in the nephrotic animals, indicating that a real enhancement of synthesis had occurred. The meaning of increased cholesterol hepatic content is discussed, as well as the possible relationship between enhanced protein and cholesterol hepatic synthesis.