Figure 1. Whole body SOAT2 knockout and intestine-specific, but not liver-specific SOAT2 knockout reduces cholesterol absorption.

(A) Fractional cholesterol absorption was determined by the dual isotope method. After consuming diet for a total of 8 weeks, each mouse was gavaged with 50 μL soybean oil containing 0.055 μCi of [¹⁴C]-cholesterol and 0.135 μCi of β-[³H]-sitosterol. Mice were then housed individually in wired-bottom cages for three days. Fecal samples were collected and fractional absorption was calculated as $100\times ({}^{14}\mathrm{C}/{}^3\mathrm{H}\text{dose}-{}^{14}\mathrm{C}/{}^3\mathrm{H}\text{feces})/({}^{14}\mathrm{C}/{}^3\mathrm{H}\text{dose})$. (B) About 50 mg of grounded feces were saponified for an hour. Lipids were extracted with hexane. Fecal neutral sterol loss was quantified by GLC using 103 μg of 5-alpha cholestane as an internal standard. +/+: SOAT2^+/+LDLr^−/−; fl/fl: SOAT2^fl/flLDLr^−/−; −/−: SOAT2^−/− LDLr^−/−; L-/L-: SOAT2^L-/L-LDLr^−/−; SI-/SI-: SOAT2^SI-/SI-LDLr^−/−. Data represent the mean ± SEM from 14 to 16 mice per genotype. Bars not sharing common letters differ with P < 0.05.