Cholesterol-ascorbic acid interactions in guinea pig liver homogenates, and in the in situ perfused liver: relationship between ascorbic acid status and cholesterol and bile acid synthesis from mevalonate.

ABSTRACT

Cell free homogenates, and in situ perfused livers were used to study cholesterol synthesis and catabolism in control and latently scorbutic guinea pigs. In the homogenate studies, cholesterol synthesis from (2-14C) mevalonate was significantly depressed in latently scorbutic guinea pigs when compared to controls (0.02 less than p less than 0.05). Synthesis of cholesterol from (1-14C) acetate and n (1-14C) octanoate was minimal in guinea pigs. In the in situ liver perfusions, the synthesis of cholesterol from (2-14C) mevalonate was 40% lower in latently scorbutic guinea pigs than in control animals (p less than 0.005). The synthesis of cholesterol from (1-41C) acetate did not show the same clear cut effect. Bile acid production in the in situ perfused liver was unexpectedly higher in the latently scorbutic animals than in control animals (p = 0.005), although the incorporation of the label from (2-14C) mevalonate into the bile acids from the two groups was not significantly different. This finding led to the latently scorbutic group having a far lower specific activity in the bile acid fraction than the replete group.