Effect of Continuous Darkness on Cholesterol Biosynthesis in Rat Liver Slice

Abstract

Male rats of wistar strain, weighing about 100 g, were divided into the following 4 groups; 1) normal control rats, 2) blinded rats by removal of their both eye balls, 3) normal rats housed in complete darkness and 4) blinded rats housed in complete darkness. All of these animals were kept at a constant temperature of 20°C for 72 days.
The cholesterol synthesis from acetate^-14C by rat liver slice was found to be raised above the control level in blinded rats, normal rats housed in complete darkness and blinded rats housed in complete darkness. There was no difference in biosynthesis between normal rats housed in complete darkness and blinded rats housed in complete darkness.
The cholesterol synthesis from mevalonic acid^-14 was slightly increased above the control level in normal rats housed in complete darkness.
A rate controlling step in cholesterol biosynthesis appears to lie between acetate and mevalonic acid.