LONG-TERM EFFECTS OF PRENATAL AND NEONATAL ADMINISTRATION OF 5BETA-DIHYDROTESTOSTERONE ON NORMAL AND NEOPLASTIC MAMMARY DEVELOPMENT IN MICE

  • 1 January 1977
    • journal article
    • research article
    • Vol. 37  (12) , 4456-4459
Abstract
The long-term effects on mammary glands of 5.beta.-dihydrotestosterone, considered to be biologically inactive, were studied in female SHN mice with mammary tumor virus. 5.beta.-Dihydrotestosterone was administered to mothers for 4 days from days 12-15 of pregnancy (prenatal treatment) and pups for 5 days of postnatal life (neonatal treatment) at daily doses of 1 mg and 200 .mu.g, respectively. Neonatal treatment resulted in marked stimulation of spontaneous mammary tumorigenesis. All neonatally treated mice had palpable mammary tumors by 6.2 mo. of age, when mammary tumor incidences in the control mice and mice treated prenatally with 5.beta.-dihydrotestosterone were 21.1 and 6.3%, respectively. Neonatal treatment promoted normal and preneoplastic mammary growth and pituitary prolactin secretion and induced ovarian anovulatory syndrome in all mice. Prenatal treatment also increased the number of mammary hyperplastic alveolar nodules and induced a delayed anovulatory syndrome. Perinatal treatment with 5.beta.-dihydrotestosterone can induce such irreversible changes in the mammary glands, pituitary gland, ovaries and genital tracts as those seen with other biologically active steroid hormones.