Puromycin inhibition of cholesterol absorption in the rat

The effect of puromycin on the intestinal absorption of cholesterol has been studied in rats with indwelling catheters in the left thoracic lymphatic duct. Puromycin administration to female rats produced a marked depression of cholesterol absorption under conditions where the absorption of simultaneously administered fatty acid was also dramatically inhibited. The same treatment of male rats also produced a significant depression in cholesterol absorption, but was without effect on absorption of the fatty acid. Despite the depressions of lipid absorption in puromycin-treated animals, there was no accumlation of either cholesterol or fatty acid in the intestinal mucosa of either sex. Actinomycin D treatment of fasting male and female rats, receiving constant infusions of saline, had no effect on the rate of lymph production. This suggest that altered lymph production was not responsible for the depressed lipid absorption observed in fed animals treated with protein synthesis inhibitors. The selective inhibition of cholesterol absorption in male rats also precludes the possibility that the major effect of the inhibitor is on delayed gastric emptying.