Effect of herpesvirus type 2 and hormonal imbalance on the uterine cervix of the mouse.

BALB/c mice were treated with different combinations of hormones (estrogens, progesterone, and Enovid) and herpesvirus type 2 (HSV-2). Characteristic cytological changes of herpesvirus infection were observed in 40% of 140 mice treated with the virus; these mice had previously been immunized with HSV-2 inactivated with ultraviolet light. No significant differences were observed in the fre quency of precancerous and cancerous lesions of the cervix and/or vagina between the group treated with estrogens plus HSV-2 (47.2%) and that treated with estrogens alone (41.2%), or between the group treated with Enovid plus HSV-2 (22.6%) and that treated with Enovid alone (31.2%). No carcinomas were observed in either the group treated with progesterone alone or the two control groups, but one carcinoma was found in the group treated with progester one and HSV-2, and two carcinomas were found in the group treated with HSV-2 alone. These three carcinomas are of special interest since spontaneous cervical carcinoma in mice has not been described, and progesterone has been found to exert a protective effect against chemical carcino gens in the mouse cervix. These results suggest that, at least in these three animals, HSV-2 may have a role in tu mor induction.