Regulation of cholesterol synthesis and 3-Hydroxy-3-methylglutaryl CoA reductase in the mouse submandibular gland

Abstract

We have investigated the rate of cholesterol biosynthesis from (1-¹⁴C) acetate and the activity of HMG-CoA reductase in microsomal preparation from the submandibular gland of mice. Mice had been subjected to diurnal light cycling, fasting for 72 hr., germ-free and cariogenic diets.
The results were as follows;
1. Mice at the mid-dark phase showed a higher rate of cholesterol synthesis and HMG-CoA reductase activity than those at the mid-light phase.
2. Germ-free mice had an increase of the rate in cholesterol synthe sis to about 88%, and the activity of HMG-CoA reductase to about 130% of control values.
3. The feeding of a cariogenic diet and fasting for 72hr. resulted in the inhibition of cholesterol synthesis and HMA-CoA reductase activity.
This data supports the concept of the rate-limiting nature of HMC -CoA reductase in the cholesterol synthetic pathway of the submandibular gland of mice.