Adenovirous type 9-induced tumorigenesis in the rat mammary gland related to sex hormonal state
Adenovirus type 9 was inoculated sc into newborn Wistar/Furth rats, divided into four groups: (1) six male rats, not treated further; (2) 11 male rats, castrated at 4 weeks of age; (3) 12 male rats, castrated at 4 weeks of age and subsequently treated repeatedly with estrogen; and (4) 12 female rats, not treated further. All of the rats in group 3 developed mammary hyperplasia and tumors (fibroade