Vitamin A deficiency and the ubiquinone and substance SC contents of rat liver: the time factor

Abstract

Weanling rats placed on a vitamin A-deficient diet reached a weight plateau after a variable time. Food consumption began to fall after about 14 days in those animals which reached the plateau earlier than 27 days after weaning. Animals which took longer to become stationary in weight began to lose appetite about 4 days before growth ceased. Anorexia became marked only in animals rapidly losing weight. Groups of deprived animals were killed at 5, 11, 20, 28 and 39 days while still growing; other groups were killed at the weight plateau and others at a time when they were losing weight. Chromatographic examinations of liver unsaponifiable matter showed: (a) a rise in sterol content only at or beyond the weight plateau; (b) a rise in substance SC which became marked when growth had slackened or ceased; (c) a progressive rise in ubiquinone; the increase was already definite in the 11-day group and when the phase of declining weight was reached the concentration averaged 5 times the concentration seen in the group of rats killed 5 days after weaning. The amount of a hydrocarbon fraction showing selective absorption at 260 mu also increased steadily with the rising ubiquinone concentration.