Radiation-Induced Hair Follicle Damage and Tumor Formation in Mouse and Rat Skin.

Abstract

This' report was prepared as an account of work I sponsored by the United States Government. Neither i the United States nor the United States Atomic Energy Commission, nor any of their employees, nor any of their : contractors, subcontractors, or their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness or usefulness of any information, apparatus, product or process disclosed, or represents that its use would not infringe privately owned rights.

Adnexal Participation in Formation of Cutaneous Tumors following Topical Application of 9, 10‐Dimethyl‐Benzanthracene

“…The cutaneous response to carcinogenic agents, whether chemical or physical, consists mainly of epidermal alterations, with the formation of papillomas and squamous cell carcinomas (Shubik et al 1953, Della Porta et al 1960, Albert et al 1972. Nonepidermal tumors are rare, the only exception being basal cell carcinomas induced by different polycyclic hydrocarbons, i.e.…”

Tumorigenic action of beta, proton, alpha and electron radiation on the rat skin

“…A consistent finding was the localized dose patterns were less oncogenic than uniform patterns for low linear energy transfer (LET) radiation, electrons (2) and X-rays (4), but not for high LET protons (9). It was estimated from geometrical considerations that the interaction distance between irradiated and unirradiated tissue was approximately 170 microns and mice are less sensitive.than rats (10).…”

“…Rat skin which has been studied extensively as a model for carcinogenesis by ionizing radiation was recently shown to be susceptible to tumor induction by 254 nm UV and 275-375 nm UV (48). The suggestion that dimers might be involved in oncogenesis requires further study in tissues where dimers and tumors can be determined separately.…”

“…A decrease in the amount of extractable DNA after UV exposure has been observed in a number of cell systems, and this effect is usually attributed to DNA-protein cross-linking 9% per 105 ergs/mm2 for 275-375 nm UV and 26.2% per 105 ergs/mm2 for 254 nm UV where the two radiation sources used were identical to the sources used in the present experiments.Other inve6tigators have reported values between 10 and 30% dimers per 105 ergs/mm2 for 254 nm UV(58).The discrepancy between in vivo and in vitro results is probably associated with differential UV absorption in the superficial layers of the epidermis which greatly modifies the dose to the basal cell layer for the same incident energy. Th UV transmission through the epidermis was measured in a separate experiment(48). The in vivo dimerization data in the present study can be corrected for epidermal attenuation by dividing the observed dimer percentages by the fraction of UV transmitted to the basal cell layer.…”

TUMORIGENIC ACTION OF BETA, PROTON, ALPHA, AND ELECTRON RADIATION ON THE RAT SKIN. Progress Report, August 1, 1971--July 31, 1972.

“…In previous work under the present contract, a number of significant results have been obtained which will now be summarized (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16) . For rat skin in the resting phase of hair growth, skin tumors were produced only if the radiation penetrated at least to a depth of about 0.3 mm which roughly corresponded to the depth of the follicles (3).…”