Fig. 1.
Intestinal overexpression of SR-BI decreases plasma cholesterol, but does not alter intestinal cholesterol absorption. Male WT and SR-BIhApoCIII-ApoAIV-Tg (SR-BI) mice littermates were fed diets containing either 0.015% or 0.2% cholesterol (w/w) for a period of 8 weeks. A: Western blot analysis of liver and jejunal homogenates (n = 3 per group) from mice fed 0.015% cholesterol for 2 weeks. B: Immunolocalization of SR-BI in the mouse jejunum. Sections (6 μm) of mouse jejunum were fixed with 3.7% formaldehyde/PBS, permeabilized with 0.05% Tween 20, and stained with a polyclonal antibody raised against SR-BI to determine tissue and subcellular localization; blue indicates nucleus, red indicates SR-BI. C: Total plasma cholesterol and HDLc in 6 week old chow-fed mice (Chow) or mice fed 0.015% or 0.2% cholesterol (Chol) for 4 weeks. D: Fractional cholesterol absorption measured by fecal dual-isotope method, and mass fecal neutral sterol loss (FNSL) determined by gas-liquid chromatography measured after 6 weeks on diet. Data in panels (C) and (D) represent the mean ± SEM from 6 to 10 mice per group. *Significantly different from WT mice within each diet group (P < 0.05).