2.1. Experimental animals and measurement of general parameters

A total of 20 male Sprague-Dawley (SD) rats, aged 6–8 weeks, were obtained from the Chongqing Medicine University Medical Laboratory Animal Center and housed in a room at 22–25°C with 50–60% relative humidity and a 12 h light/dark cycle. The rats were randomized into the following two groups: the normal control group (NC), which was provided basic feed, and the high-fat diet group (HFD), which was provided a high-fat diet (2% cholesterol, 0.3% deoxysodium cholate, 7.5% lard, 0.2% propylthiouracil, 5% egg yolk powder, and 85% basal feed). The body weights of rats were recorded every week. Blood, urine, and renal tissues were harvested after 4 and 10 weeks. The levels of blood lipids (total cholesterol [TC], triglyceride [TG], and low-density lipoprotein cholesterol [LDL-c]) were tested using a fully automatic biochemical analyzer. The rats were kept alone in metabolic cages, and 24 h urine samples were collected to quantitatively analyze the level of 24 h urinary protein using Coomassie brilliant blue staining. Glomerular morphology was observed using an electron microscope, and protein was extracted to measure CD36 expression using western blot analysis.