Effect of steroid hormones on the in vivo incorporation of glycine-2-14C into solid Ehrlich tumor, kidney, and liver.

Abstract

The effect of steroid hormones for the nucleic acid and protein metabolism of solid Ehrlich tumor was studied by use of glycine-2-14C. The in vivo incorporation of glycine-14C into the nucleic acid and protein fractions of tumor tissue increased markedly 24 hr after the administration of 1 mg testosterone. Concomitantly, the increase of cellular constituents occurred successively in the order of RNA, protein, and DNA in the hormone-treated tumor as compared to the control tumor. The administration of 1 mg hydrocortisone acetate (HCA) resulted in a remarkable decrease in the incorporation of the tracer into tumor tissue 12 hr after the hormone injection. This inhibitive effect of HCA on tumor was more profound and persistent in male than in female mice, indicating that the hormone responsiveness of male tumor to HCA is much higher than that of female tumor. The decrease in the incorporation of glycine was also associated with the reduction of protein, RNA, and DNA contents of tumor tissue. Although there were some alterations in the tumor treated with estradiol, these changes were not in good accordance with the findings on the long-term experiment, in which the tumor growth was suppressed by the same hormone. It is indicated that the inhibitive effect of estradiol on tumor is a process requiring time and is to be distinguished from that of HCA. The differential actions of the three hormones were compared in the liver, kidney, and solid tumor. The significance of these findings was discussed in the light of the molecular biology of steroid hormones.