[Influence of a long-term load of dietary cholesterol on the rat kidney]

The involvement of hyperlipidemia in aggravation of nephrosis has remained controversial. In this study, to examine the influence of cholesterol on the kidney, normal SD rats were loaded with a normal diet(4.4% fat, 0.09% cholesterol) plus 0.25% cholesterol for 10 months, and the urinary excretion of protein, blood cholesterol level and histological renal changes were compared with those in the control group given the normal diet alone. The urinary protein excretion was increased after 4 months of cholesterol loading and was about 6 times the control value at the end of the study(10 months). At 10 months, the blood levels of total, HDL- and LDL + VLDL-cholesterols were also increased, and the arteriosclerosis index(HDL/LDL + VLDL ratio) was about 1.3 times the control value. Histologically, segmental lesions of glomeruli containing sclerosis/PAS positive material were stronger than in the control animals. Thus, this study revealed increased blood cholesterol and urinary protein excretion and aggravated histological changes of the kidney in rats given a long-term cholesterol load, suggesting that cholesterol may be a risk factor affecting the kidney.