Activity of Microsomal Heme Oxygenase in Liver and Spleen of Ascorbic Acid-Deficient Guinea Pigs

Abstract

Hepatic heme oxygenase activity was significantly altered in vitamin C-deficient guinea pigs. It was increased 2-fold after 14 days and decreased by 20% after 21 days of deprivation of the vitamin (always in comparison with the control value). The apparent Km of the enzyme was altered in the course of ascorbic acid deficiency. The data of hepatic heme oxygenase activity correpond to previous results on the metabolism of hepatic cytochrome P-450 in different stages of ascorbic acid deprivation. Splenic heme oxygenase activity decreased progressively, arriving at 50% of the control value after 21 days of vitamin C omission; its apparent Km remained unaltered.