Effect of age on the activity of glucose-6-phosphate dehydrogenase in different tissues of rat

Abstract

Spectrophotometric determination of the activity of glucose-6-phosphate dehydrogenase was made in the liver, brain (cerebral hemisphere), heart, kidney cortex and skeletal muscle (gastrocnemius) of 4-, 14-, 42-, 63- and 96-week-old female rats. The activity of the enzyme (units/g. wet wt.) was found to increase during the growth period (4-14 weeks) in all the tissues except in skeletal muscle. The activity continued to increase up to 63 weeks in the kidney cortex. The activity at 96 weeks was lower than that at 14 weeks in all the tissues. It is concluded that the decrease in the activity of this enzyme of the hexose monophosphate pathway after 14 weeks may be due to cessation of mitosis in these tissues for which deoxyribose is necessary.