Alteration of regression of cholesterol accumulation in rats by dietary pectin

Male, Wistar rats (50-74 g) were given a semi-purified diet containing cholesterol (10 g/kg diet) for 4 weeks, groups of control and experimental animals killed, and the remainder of the cholesterol-fed animals given either a semi-purified cholesterol-free diet without a fibre source or a similar diet with pectin (50 g/kg diet) for 8 weeks. Animals were killed at 2-week intervals and serum and liver cholesterol and triglycerides, faecal neutral steroids and acidic steroids measured. Animals given pectin had significantly lower serum cholesterol levels than animals given the basal diet after 4 and 6 weeks. Both experimental groups efficiently decreased their liver cholesterol levels during regression. Bile acid excretion was elevated in both groups, especially in rats receiving pectin, but neutral steroid excretion was unchanged. The increase in bile acid excretion was primarily in the form of chenodeoxycholic acid and its metabolites. This increased bile acid excretion is postulated to result from stimulation of the normal mechanism for increased steroid excretion in the rat, i.e. a change in the value of cholic: chenodeoxycholic acid or from a mechanism not yet elucidated.