EFFECTS OF HORMONES ON HEPATIC GLUCOSE 6-PHOSPHATE DEHYDROGENASE OF RAT

Abstract

The effects of hormones on the total activity and the isozyme pattern of glucose 6-phosphate dehydrogenase of livers of normal, castrated and adrenalectomized rats were studied. Sex difference in total enzyme activity and in the activity of one of the seven isozymes separated electrophoretically (band D enzyme) has been confirmed. Orchidectomy did not affect appreciably the enzyme activity; ovariectomy of young rats reduced the enzyme activity and abolished the sex difference. Adrenalectomy slightly reduced the enzyme activity in male and female rats, but did not eliminate the sex difference in isozyme pattern. Injection of dehydroepiandrosterone into normal and castrated female rats lowered the enzyme activity, whereas administration of estradiol benzoate to normal and castrated male rats strikingly increased the enzyme activity. In estradiol-treated males the isozyme pattern become female type. The effect of estradiol was inhibited by puromycin. Estradiol stimulated but dehydroepiandrosterone had little effect on hepatic 6-phosphogluconate dehydrogenase activity.