Changes in the cholesterol content of high-density plasma lipoproteins in guinea pigs in the presence of a raised exogenous cholesterol intake and different degrees of vitamin C saturation.

The cholesterol content of the high-density plasma lipoproteins (d over 1.1 g.cm-3) of guinea-pigs with experimental vitamin C deficiency, followed by realimentation with suboptimal (1 mg/animal per day) or optimal (10 mg/animal per day) doses of L-ascorbic acid for 6-9 weeks in the continued presence of an elevated alimentary cholesterol intake (0.5 g/kg diet), did not exceed 5% of the total plasma cholesterol concentration and did not alter significantly with changes in the degree of vitamin C saturation of the organism. The maximum total body tissue cholesterol concentrations were found in C-deficient guinea-pigs (plasma, adrenals) and in the group with partial vitamin C deficiency (liver, brain); the lowest values were found in the group whose organism was fully saturated with vitamin C. Under conditions of a raised cholesterol intake, ascorbic acid stimulated its elimination from the organism, but did not affect the proportion of plasma cholesterol bound in high-density lipoproteins.