Fibroma induction in rat skin following single or multiple doses of 1.0 GeV/nucleon 56Fe ions from the Brookhaven Alternating Gradient Synchrotron (AGS).
Rat skin was exposed to the plateau region of the 1.0 GeV/nucleon 56Fe beam at the Brookhaven AGS. Rats were irradiated or not with single of split doses of 56Fe or argon; some 56Fe-exposed rats were fed 250 ppm retinyl acetate continuously in the lab chow beginning 1 week before irradiation. All lesions were noted, photographed and identified for eventual histological diagnosis. The preponderance of the tumors so far are fibromas. The data show that single doses of 56Fe ions are 2 or 3 fold more effective than argon in producing tumors at 4.5 Gy but are about equally effective at 3.0 Gy and 9.0 Gy. The presence of 250 ppm retinyl acetate in the lab chow reduced the incidence of tumors by about 50-60% in comparison to groups exposed only to the radiation. These are preliminary findings based on only about one-fourth the eventual number of tumors expected.
Burns
F J
FJ
New York University School of Medicine, Departments of Environmental Medicine and Dermatology, New York, NY 10016, USA.
Zhao
P
P
Xu
G
G
Roy
N
N
Loomis
C
C
D000818:Animals; D016588:Anticarcinogenic Agents / Q000627:therapeutic use; D004224:Diterpenes; D004307:Dose-Response Relationship, Radiation; D005350:Fibroma / Q000209:etiology* / Q000517:prevention & control; D020450:Heavy Ions; D007501:Iron; D018499:Linear Energy Transfer; D009381:Neoplasms, Radiation-Induced / Q000209:etiology* / Q000517:prevention & control; D051381:Rats; D000084562:Retinyl Esters; D012867:Skin / Q000528:radiation effects*; D012878:Skin Neoplasms / Q000209:etiology* / Q000517:prevention & control; D017356:Synchrotrons; D014801:Vitamin A / Q000031:analogs & derivatives* / Q000627:therapeutic use
D016588:Anticarcinogenic Agents; D004224:Diterpenes; D000084562:Retinyl Esters; D014801:Vitamin A; C009166:retinol acetate; D007501:Iron