L-Histidine-Induced Facilitation of Cholesterol Biosynthesis in Rats 1

Summary

A diet supplemented 5% with L-histidine induces hypercholesterolemia in rats. To examine the mechanism involved, L-histidine was added to either a chow or fat-free diet and fed to rats for 18 days. After 2 days of fasting, the rats were refed the same diet for three days. There was a ninefold increase in the incorporation of [¹⁴C] acetate into the nonsaponifiable fraction in the 5,000g hepatic fraction of histidine-supplemented chow-fed rats compared to controls. The increase in the incorporation of the labeled substrate into the digitonin-precipitable fraction was seven- to eightfold. The incorporation of [¹⁴C]mevalonate was increased by sevenfold in both the nonsaponifiable and digitonin-precipitable fractions. Longterm histidine supplementation to fat-free diet did not affect the incorporation of either [¹⁴C] acetate or [¹⁴C] mevalonate into these fractions.

We wish to thank Ms. Cynthia Birch for her technical assistance.