This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Kelner, A. Articles by Taft, E. B. Search for Related Content PubMed PubMed Citation Articles by Kelner, A. Articles by Taft, E. B.

The Influence of Photoreactivating Light on the Type and Frequency of Tumors Induced by Ultraviolet Radiation

( Brandeis University, Waltham, Mass., and Medical Laboratories of the Collis P. Huntington Memorial Hospital of Harvard University, Massachusetts General Hospital, Boston, Mass.)

Ultraviolet light, 2537 A, is a potent inducer of skin neoplasms in albino mice. This finding is contrary to reports in the literature that 2537 A is not, or is only weakly, carcinogenic for the skin of albino mice.

Wave length 2537 A induced only carcinomas, in contrast to 2800–3100, which induced both carcinomas and sarcomas, with sarcomas predominating. Reactivating light (ca. 3600–4900 A) apparently reduced the carcinogenic action of 2537 A, but not that of 2800–3100 A. It did, however, possibly lower the incidence of carcinomas induced by 2800–3100 A. It is suggested that reactivating light may reduce carcinoma induction, by either 2537 or 2800–3100 A, but not sarcoma induction.

The exploratory experiments reported here were handicapped by the small number of animals. While the evidence for the carcinogenicity of 2537 A is convincing, that for the photoreactivation phenomena is not statistically significant, and conclusions on the photoreversibility of carcinogenesis are therefore only tentative.

^* Aided by grant C-1725 from the National Cancer Institute, and by a grant from the Brandeis University Faculty Research Fund. A preliminary account of this work was given at the 1953 meetings of the Genetics Society of America (Rec. Gen. Soc. Am., 22:82–83, 1953).

Received 4/23/56.