Abstract
Rats frequently develop various tumors, many of them malignant; the majority of tumors in the females develop in the mammary glands. In primary spontaneous tumors and lymphomas virus particles cannot be found on electron microscopic examination; transmission of the tumors by filtered extracts has not been successful. In our colonies of Sprague-Dawley rats the incidence of tumors was 22% in females and 5% in males; in Long-Evans rats the incidence of tumors and 28% in females and 10% in males. In (Sprague-Dawley x Long-Evans) F1 hybrids the incidence of tumors was 67% in females and 32% in males, about twice as high as in the parental strains. Fractionated total-body x-irradiation (150 rads five times at weekly intervals) (1 rad = 0.01 gray) increased the incidence of tumors in Sprague-Dawley rats from 22% to 93% in females and from 5% to 59% in males. In Long-Evans rats, irradiation increased the incidence of tumors from 28% to 63% in females and from 10% to 42% in males. The incidence of malignant tumors was almost twice as high in irradiated Sprague-Dawley and Long-Evans rats as compared with nonirradiated animals of the same strains. Partial shielding during irradiation had no significant effect on the incidence or on the forms of tumors developing in the irradiated animals. In striking contrast to results of experiments carried out on mice, the incidence of leukemia and lymphomas was not increased in the irradiated rats, as compared with control animals.
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Selected References
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- BOND V. P., CRONKITE E. P., LIPPINCOTT S. W., SHELLABARGER C. J. Studies on radiation-induced mammary gland neoplasia in the rat. III. Relation of the neoplastic response to dose of total-body radiation. Radiat Res. 1960 Mar;12:276–285. [PubMed] [Google Scholar]
- BOND V. P., SHELLABARGER C. J., CRONKITE E. P., FLIEDNER T. M. Studies on radiation-induced mammary gland neoplasia in the rat. 5. Induction by localized irradiation. Radiat Res. 1960 Aug;13:318–328. [PubMed] [Google Scholar]
- CRAIN R. C. Spontaneous tumors in the Rochester strain of the Wistar rat. Am J Pathol. 1958 Mar-Apr;34(2):311–335. [PMC free article] [PubMed] [Google Scholar]
- Durbin P. W., Williams M. H., Jeung N., Arnold J. S. Development of spontaneous mammary tumors over the life-span of the female Charles River (Sprague-Dawley) rat: the influence of ovariectomy, thyroidectomy, and adrenalectomy-ovariectomy. Cancer Res. 1966 Mar;26(3):400–411. [PubMed] [Google Scholar]
- GROSS L. Attempt to recover filterable agent from x-ray induced leukemia. Acta Haematol. 1958 Jun;19(6):353–361. doi: 10.1159/000205455. [DOI] [PubMed] [Google Scholar]
- GROSS L., ROSWIT B., MADA E. R., DREYFUSS Y., MOORE L. A. Studies on radiation-induced leukemia in mice. Cancer Res. 1959 Apr;19(3 Pt 1):316–320. [PubMed] [Google Scholar]
- GROSS L. [Serial cell-free passage of a radiation-activated mouse leukemia agent]. Proc Soc Exp Biol Med. 1959 Jan;100(1):102–105. doi: 10.3181/00379727-100-24538. [DOI] [PubMed] [Google Scholar]
- Gross L., Schidlovsky G., Feldman D., Dreyfuss Y., Moore L. A. C-type virus particles in placenta of normal healthy Sprague-Dawley rats. Proc Natl Acad Sci U S A. 1975 Aug;72(8):3240–3244. doi: 10.1073/pnas.72.8.3240. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Gross L. Viral etiology of cancer and leukemia: a look into the past, present and future--G.H.A. Clowes Memorial Lecture. Cancer Res. 1978 Mar;38(3):485–493. [PubMed] [Google Scholar]
- KIM U., CLIFTON K. H., FURTH J. A highly inbred line of Wistar rats yielding spontaneous mammo-somatotropic pituitary and other tumors. J Natl Cancer Inst. 1960 May;24:1031–1055. [PubMed] [Google Scholar]
- KOLETSKY S., GUSTAFSON G. E. Whole body radiation as a carcinogenic agent. Cancer Res. 1955 Feb;15(2):100–104. [PubMed] [Google Scholar]
- Kinkel H. J. Spontantumoren bei Sprague-Dawley-Ratten. Z Versuchstierkd. 1971;13(2):97–100. [PubMed] [Google Scholar]
- LIEBERMAN M., KAPLAN H. S. Leukemogenic activity of filtrates from radiation-induced lymphoid tumors of mice. Science. 1959 Aug 14;130(3372):387–388. doi: 10.1126/science.130.3372.387. [DOI] [PubMed] [Google Scholar]
- NOBLE R. L., CUTTS J. H. Mammary tumors of the rat: a review. Cancer Res. 1959 Dec;19:1125–1139. [PubMed] [Google Scholar]
- Prejean J. D., Peckham J. C., Casey A. E., Griswold D. P., Weisburger E. K., Weisburger J. H. Spontaneous tumors in Sprague-Dawley rats and Swiss mice. Cancer Res. 1973 Nov;33(11):2768–2773. [PubMed] [Google Scholar]
- Rosen V. J., Castanera T. J., Kimeldorf D. J., Jones D. C. Renal Neoplasms in the Irradiated and Nonirradiated Sprague-Dawley Rat. Am J Pathol. 1961 Mar;38(3):359–369. [PMC free article] [PubMed] [Google Scholar]
- THOMPSON S. W., HUSEBY R. A., FOX M. A., DAVIS C. L., HUNT R. D. Spontaneous tumors in the Sprague-Dawley rat. J Natl Cancer Inst. 1961 Nov;27:1037–1057. [PubMed] [Google Scholar]
