[A comparison of the effect of hydrocortisone and corticosterone on histone and chromatin DNA biosynthesis in regenerating rat liver].

Thymidin incorporation into DNA was depressed and glycin incorporation into histone proteins was decreased after the treatment of rats with hydrocortisone and corticosterone for 4 days (for 3 days before and on the day of partial hepatectomy). No significant differences in the action of these glucocorticoids on biosynthesis of DNA and histones in the course of regeneration were noted at the periods under study. There was no decrease in histones and nucleoprotein in comparison with control 6 hours after the operation at the time when the synthesis of DNA-like RNA was elevated. Apparently DNA synthesis was not imperative for biosynthesis of histone proteins, in any way--for the arginine-rich fraction of histones.