Studies on the expression levels of sterol-metabolizing enzymes in the obese model SHR/NDmcr-cp rats.

1. Expression levels of four key enzymes of cholesterol metabolism, namely 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase, lanosterol 14-demethylase (CYP51), cholesterol 7alpha-hydroxylase (CYP7A1) and sterol 12alpha-hydroxylase (CYP8B1), in metabolic syndrome model rats (SHR/NDmcr-cp) were examined. 2. Decreased expression of CYP51, which may be linked to the development of obesity, was found in the rats. 3. Expression of CYP8B1 was significantly higher in young rats. 4. No substantial change was observed in the mRNA levels of the dominant rate-limiting enzymes of sterol metabolism, namely HMG-CoA reductase and CYP7A1, in the rats. 5. These findings suggest that the expression levels of two key enzymes managing the downstream parts of the cholesterol-metabolizing pathways are altered in the rats, although little change was observed in the expression levels of the dominant rate-limiting enzymes of cholesterol metabolism.