Plasma cholesterol levels in C57BL6/J and LDLR-/- mice fed low- or high-cholesterol diets. Two-month old C57BL/6J wild type (C57BL) or LDLR-/-mice were fed either low (LCD) or high (HCD) cholesterol diets for 4 or 10 months. Plasma cholesterol was determined at baseline (Pre-diet, n = 11/group), as well as after 4 (n = 11/group; except n = 12, LDLR-HCD) or 10 (n = 6, C57BL-LCD; n = 6, C57BL-HCD; n = 5, LDLR-LCD; and n = 2, LDLR-HCD) months. Asterisks indicate groups different from C57BL-LCD at each time point (p < 0.05). Results are discussed further in the text.