[Absorption cooefficient for dietary cholesterol, the fundamental parameter of cholesterol dynamic equilibrium in rats].

By an isotopic equilibrium method turnover rates of rats cholesterol have been determined in 30 various experimental conditions. A deductive analysis of these overall old data discovers that absorption coefficient of dietary cholesterol is a determinative parameter of cholesterol dynamic equilibrium. Synthesis which takes places chiefly in the intestine, fecal external secretion and fecal excretion of cholesterol are linearly increasing when the absorption coefficient is decreasing. Two types of exception have been noted. The most interesting concerns the case where there is a supplementary synthesis. For pregnant of lactating female rats placenta or mammary glands are directly interested. For rats with ligated bile duct or feed with cholestryramine, liver must be incriminated. These two last cases are the alone on 30 where hepatic synthesis play very probably a notable role in the dynamic equilibrium of cholesterol.