Hypocholesterolemic effect of methyltestosterone in rats

In rats fed a stock diet, the oral administration of 17α-methyltestosterone (0.05% of the diet) produced a 46% average reduction of serum total cholesterol concentration. The ratio between the cholesterol content of the α- and β-lipoprotein fractions remained unchanged. In rats made mildly hypercholesterolemic by the addition of 1% cholesterol to the stock diet, the oral administration of 0.1% methyltestosterone prevented the rise in serum cholesterol concentration. This effect resulted primarily from a reduction of the cholesterol content of the α-lipoprotein fraction. The production of a more intense hypercholesterolemia by the administration of 1% cholesterol plus 0.5% cholic acid abolished the hypocholesterolemic action of 0.1% methyltestosterone. Analyses of the cholesterol content of the liver and intestinal wall indicated, in animals on both low and high cholesterol diets, that methyltestosterone did not exert its effect by producing a redistribution of the cholesterol between the serum and the tissues examined.