Animal Model Screening for Hyperlipidemic ICR Mice.

This study aimed to establish a hyperlipidemia model in ICR mice using a homemade high-fat diet. It further investigated hyperlipidemia-related indicators in control and model mice at various feeding durations to determine the optimal time frame for successful model establishment. Sixteen male ICR mice were introduced at intervals of 3 weeks, starting from weeks 0, 3, 6, 9, and 12. The control group was fed a standard diet, while the model group received a homemade high-fat diet to induce hyperlipidemia. Blood lipid related indices were detected at 15 weeks. The liver, scapular fat, abdominal fat, and epididymal fat were harvested to calculate the organ index. The contents of T-CHO, TG, and TBA in the liver were measured. HE staining was used to observe pathological changes in liver tissue and white adipose tissue, while Oil Red O staining was used to observe lipid droplets in liver tissue. The mRNA and protein expression of SREBP-2, insig1, HMGCR, LXRα, ABCA1, and CYP7A1 in the liver were detected by RT-qPCR and Western Blot. In the model group, blood lipid levels significantly increased by the 9th week, aligning with pathological changes indicative of hyperlipidemia. The mRNA and protein expression levels of SREBP-2, Insig-1, HMGCR, LXRα, ABCA1, and CYP7A1 were markedly elevated at 9 weeks and remained relatively stable thereafter. This study provides a reliable reference for determining the optimal establishment time of hyperlipidemia models and for in vivo hyperlipidemia animal experiments.