THE INFLUENCE OF CORTISONE ON CELL DIVISION

¹ The Sir William Dunn School of Pathology, Oxford

1. The influence of large doses of cortisone on the mitotic activity which normally occurs after partial hepatectomy in mice was studied. At the same time the changes in liver protein, fat, glycogen and nucleic acids were followed.

2. In the mice given cortisone, mitoses were rarely seen 2 days after operation, whereas at that time the mitotic rate in controls was very high. Later, at 6 days, this difference was not observed.

3. Although the increase in weight of the liver after partial hepatectomy was the same in experimental and control mice, in the former this was largely due to a deposition of fat and glycogen. There was, however, some new formation of protein in cortisone-treated mice.

4. RNA regeneration was nearly normal; DNA, however, failed to regenerate in mice given cortisone.

5. Cell division occurring normally in the endothelium of the crypts of Lieberkühn was not inhibited by cortisone in large doses.

6. Mitoses were seen in lymphoid follicles in mice receiving large doses of cortisone.

7. The conclusion that cortisone does not inhibit mitoses in every tissue is discussed.

Note:

The authors wish to thank Mr. J. Kent for his help with the animal operations, Mr. H. W. Wheal and Miss Eileen Page for technical assistance, and Mr. D. W. Jerrome for preparing the histological sections. The photomicrographs were taken by Mr. B. H. Glass.

The cortisone used in these experiments was provided from a generous gift made to the Medical Research Council by Merck & Co. Inc.