Prolactin and 3-methylcholanthrene induced cervical carcinoma. Effect of bromocriptine.

Female mice of the NMRI strain were injected with estradil for the first five days after birth (estrogenized animals) and ovariectomized at the ages of 6-9 weeks. One week later, a cotton thread impregnated with 3-methylcholanthrene was inserted into the uterine cervix. Starting on the day of insertion of the thread, and for a further 6 days, the females were injected with estradiol (E2), ovine prolactin (P), or 2-bromo-alpha-ergokryptine mesylate (bromocriptine). Controls were injected with vehicles only. The animals were killed 4 or 8 weeks after insertion of the thread, and the uterine cervix was serially sectioned. A combined treatment with E2 and P resulted in an increased incidence of invasive epithelial lesions in the uterine cervix. This incidence was higher than in controls or females injected with either hormone separately. Bromocriptine reduced the incidence of invasions, and this reduction with either hormone separately. Bromocriptine reduced the incidence of invasion, and this reduction could not be restored to the contrl level by a simultaneous treatment with E2 anrogenized females was higher than that reported in an earlied study using non-estrogpenized females.