CYP7A1 and Hypercholesterolemia: In this study we examined potential mechanisms underlying this affect, specifically alterations in expression of the LDL-receptor (LDL-R), 3-hydroxy-3-methyl glutaryl (HMG)-CoA reductase and cytochrome P450 7α-1 (CYP7α-1), using a rat model of hypercholesterolemia.