Acute Hypervitaminosis A in Guinea Pigs. I. Effects on Acid Hydrolases

Acute hypervitaminosis A was induced in guinea pigs by oral administration of Vit. A. This treatment caused much of the activity of acid phosphatase, beta-glucuronidase and cathepsin to become unsedimentable at 15,000 g in homogenates prepared in 0.25M sucrose. Lysosome-rich fractions of hypervitaminotic livers released beta-glucuronidase and cathepsin more readily into the incubation medium in vitro than did control fractions. These events were accompanied by increases of serum beta-glucuronidase, and are compatible with a direct effect of excess Vit. A on lysosomes.