Inhibitory effect of isocholesterol on the absorption of cholesterol.

The presence on carbon-3 of a free hydroxyl group that may be esterified is a common characteristic of the known sterol inhibitors of cholesterol absorption. The 30-carbon stcrols found in wool fat possess such a group, but differ from the previously demonstrated inhibitors of cholesterol absorption in that they do not form insoluble precipitates with digitonin. To determine whether these substances would influence cholesterol absorption, "isocholesterol," a mixture of 30-carbon wool fat sterols, has been fed to the albino rat alone and in combination with cholesterol.