Age-related differential induction of tryptophan pyrrolase by hydrocortisone in the liver of male rats

Abstract

The activity and the regulatory pattern of tryptophan pyrrolase of the liver of male rats during various phases of the life span were studied with a view to investigate the differential effectiveness of hydrocortisone in relation to growth, development, and senescence of an organism. The level of this enzyme shows no significant change till adulthood but decreases significantly thereafter with increasing age. Adrenalectomy and hydrocortisone treatments decrease and increase, respectively the activity of this enzyme significantly in rats of all the ages. However, the effects of these treatments are highest in the mature rat. Induction of the enzyme by hydrocortisone is actinomycin D-sensitive.