Fig. 2.

Absorbed cholesterol is secreted in chylomicrons at different rates in C57 and FVB mice. Nonfasted female C57 and FVB mice were injected retro-orbitally with 100 μl tyloxapol (10% v/v) followed by gavage with 2 μCi [³H]cholesterol in 200 μl olive oil. A: Plasma samples were collected over the course of 7 h, and plasma radiolabel was measured by liquid scintillation counting. B: Plasma samples (7 h) were separated on a 3–20% NaBr gradient and fractionated, and [³H]cholesterol levels in each fraction were determined by liquid scintillation counting. Data represent mean ± standard deviation of triplicate mice. C: Non-fasted mice were injected retro-orbitally with equal amounts of [³H]cholesterol-labeled chylomicrons. Three h plasma samples were separated on a 3-20% NaBr gradient, fractionated, and [³H]cholesterol levels in each fraction determined by liquid scintillation counting. Data represent mean ± SD of triplicate mice.