Effect of injection of adenovirus type 12 in adult hamsters.

Large doses of adenovirus type 12 were injected intraperitoneally into adult hamsters, and development of tumors and other pathological findings were studied in comparison with those in hamsters injected when newborn. Doses of 38∼47 TCID60 per gram body weight produced tumors in 3 of 12 hamsters injected at 37∼57 days of age. A dose of 170 TCID60 per gram body weight produced tumors in one of 18 hamsters injected at 61∼71 days of age, but in none of 18 hamsters injected at 147∼174 days of age, while the same dose per gram body weight produced tumors in 24 of 26 hamsters injected when newborn. In hamsters injected at adult ages, the number of tumors per animal decreased and the latent period for tumor development became very long as compared with those in hamsters injected when newborn. Regardless of the age at the time of injection, acute inflammatory change was observed in the peritoneum which later developed into various degrees of peritoneal adhesion. Adenovirus type 3 also induced the peritoneal adhesion. Histology of tumors was studied and discussed. ∗PMID: 4226975 [PubMed indexed for MEDLINE] Copyright c ©OKAYAMA UNIVERSITY MEDICAL SCHOOL Acta Med. Okayama 20, 147-154 (1966) EFFECT OF INJECTION OF ADENOVIRUS TYPE 12 IN ADULT HAMSTERS* Yoshiro YABE**, Katsuo OGAWA***, Katsumi IWATA*** and Sakae MURAKAMI**** Institute for Cancer Research**, Second Department of Pathology*** and Department of Microbiology****, Okayama University Medical School, Okayama, Japan Received for publication, May 19, 1966 The age of animals is a very important consideration in tumor virus experiments. Human adenovirus type 12 induced tumors in hamsters when injected at birth or at very young ages, but did not when injected at adult ages1.2. In these experiments, tumors mostly developed at the site of injection suggesting that the local concentration of virus might be one of the important factors for tumor inductions. In the present experiment, large doses of adenovirus type 12 were injected into adult hamsters and the development of tumors and of other pathological changes has been studied. MATERIALS AND METHODS Virus: Adenovirus type 12, strain "Huie" was obtained from the American Type Culture Collection and adenovirus type 3, strain" G. B." was obtained from the Institute for Infectious Diseases, Tokyo University. Virus was cultured in HeLa cells. The virus culture fl uid was frozen and thawed 3 times, centrifuged at 1, 000 rpm for 5 minutes, and its supernatant was used for experiment. Virus titration: Virus fluid was diluted in tenfold series with Earle solution containing 0.5% lactalbumin hydrolyzate and 0.1?-6 yeast extract (YLE). One-tenth milliliter of each virus dilution was inoculated into HeLa cell tubes (4 tubes for each dilution) containing 1 ml of YLE as the maintenance medium. These tubes were incubated at 36. 5°C and observed for cytopathogenic effect for 5 days. The 50% tissue culture infectious dose per 0.1 ml (TCIDoo/O.l ml) was calculated by REED and MUENCH'S method• Animal: The breeding colony was established in our laboratory with Syrian hamsters from the Medical Section of Fukuyama Detachment of Japan *This work was supported by a grant CA-06813 from the National Cancer Institute, U. S. Public Health Service, and by grants from the Ministry of Education of Japan.