Abstract
The effect of subcutaneous inoculation of polyoma virus into the submandibular and dorsal regions of newborn DDO mice within 24 hours after birth was investigated in order to test specific susceptibility of that region or of the mice themselves to the virus, and following points were found.
1) Seventy-six percent of those receiving submandibular inoculations of polyoma virus developed tumor. The mean age for the appearance of the tumor was from 2 to 6 months.
2) Thirty-nine neoplasms developed among 26 mice. They were divided into 6 distinct types: 24 parotid gland tumor: 5 submandibular gland tumor: 4 sublingual gland tumor; 3 osteofibroma in the leg; 2 papillary adenocarcinoma in the mammary gland; and one osteofibroma in the mandible.
3) None of the mice that received the control material (tissue culture preparation without polyoma virus) in the submandibular region developed neoplasms.
4) The animals inoculated with polyoma virus in the back remained free of gross neoplasms during a 7-month observation period, although they did show histopathological changes in the kidney.
5) The mice which received the control material in the back did not develop any gross tumor or histopathological changes.
6) The present experiment indicates that the oncogenic effect of polyoma virus is local rather than systemic and that polyoma virus has special influence on salivary gland tissue without intermediation of other organs. Furthermore, DDO mice exhibited no specific susceptibility to polyoma virus.
