STIMULATION OF DNA SYNTHESIS IN RAT LIVER BY ADRENALECTOMY

Abstract

SUMMARY The following effects were observed in the liver of male rats in the first few days after adrenalectomy: the rate of thymidine incorporation into DNA was increased three- to fourfold in the 2 days after adrenalectomy. The mitotic index was increased 5·5-fold on the first day and 15-fold on the second day after the operation. The number of tetraploid cells rose from 40 to 68%. While the subsequent administration of cortisol, cortisone or corticosterone to the adrenalectomized animals reduced DNA synthesis to the normal level, testosterone and oestrone were without effect. It is suggested that liver growth is regulated by the concentration of corticosteroids in the blood.