LIFE SPAN, TUMOR INCIDENCE, AND INTERCAPILLARY GLOMERULOSCLEROSIS IN THE CHINESE HAMSTER (CRICETULUS GRISEUS) AFTER WHOLE-BODY AND PARTIAL-BODY EXPOSURE TO X-RAYS
For the young adult chinese hamster, about 135 days old, the mean age at death and its 99% confidence limits were found to be 1045 (887 to 1170) days for the males, and 959 (820 to 1003) days for the females. Young adults were subjected to whole-body or partial-body x-ray (250kvep) exposure. The following results apply to those hamsters alive 100 days after exposure (about 235 days of age). After a whole-body dose of about 550 rads (LD/sub 10(30)/), the decrement in median life span was about 220 days in both sexes. For each additional 100 rads (up to a total dose of 900 rais), about 140 more days of decrement occurred. The life-shortening effect therefore is relatively more severe than in other species, although the LD/sub 50(28)/ is relatively higher. Judged by survival, the anterior half of tlhe body (anterior to the xiphoid process) was much more vulnerable than the posterior half when these regions were irradiated separately. Furthermore, the response to wholebody exposure appeared to be determined largely by the dose to the anterior half of the body. A total of 49 tumors at eleven body sites was found in 309 autopsied animals, an overall incidence rate of 0.16. A significant increase resulting from irradiation was established only in the case of the ovary, where the most common tumor was the theca cell form. The data suggested the possibility of an increase in leukemia, in renal tumors, and in interstitial cell tumors of the testis. Progressive intercapillary glomerulosclerosis, a process associated with aging, was observed in the kidneys of all animals examined. This lesion was accelerated by irradiation and, in general, was similar to that described in the mouse. Study of the pancreas revealed no evidence of the histological changes commonly associated with diabetes mellitus in the Chinese hamster, nor of other degenerative or neoplastic disease. Therefore diabetes could be excluded as a cause of the renal lesions observed in aging and irradiated animals. The present results indicate that the Chinese hamster should prove to be a valuable animal for studies in radiobiology, oncology, and aging. It is easily maintained, has a low spontaneous rate of tumor incidence, and has a relatively long life span; it is susceptible to tumor induction by irradiation. (auth)
- Research Organization:
- Univ. of California, San Francisco
- Sponsoring Organization:
- USDOE
- NSA Number:
- NSA-18-019672
- OSTI ID:
- 4018011
- Journal Information:
- Radiation Res., Vol. Vol: 21; Other Information: Orig. Receipt Date: 31-DEC-64
- Country of Publication:
- Country unknown/Code not available
- Language:
- English
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