Breast Tissue Of Mice Research Articles

Immunohistochemical Localization of Catechol Methyltransferase in Normal and Cancerous Breast Tissues of Mice and Rats<xref ref-type="fn" rid="fn2">2</xref>

The immunocytochemical localization of catechol methyltransferase was determined in normal and cancerous breast tissues of inbred female Swiss-Webster mice and in normal, lactating, and cancerous breast tissues of inbred Sprague-Dawley rats. The enzyme was found to be cytoplasmically localized in ductal epithelial cells of secretory tubules in both inactive and stimulated mammary glands, in endothelial cells lining blood vessels, in fibroblasts in the connective tissue matrix, and, especially, in tumor cells. Adipose cells were nonreactive. The intensity of the immunocytochemical reaction in tumor cells was stronger than that in lactating tissues, which, in turn, was more reactive than that in normal, unstimulated breast tissues.

Cytotoxic Property of Mouse Cancer Antiserum.

ConclusionsAn immune serum prepared in rabbits against the mouse mammary carcinoma milk factor, or Bittner virus, when mixed with cancer cells for a period of 6 hours completely inhibits their growth so that transplant tumors do not develop. Control tumors developed after similar treatment of tumor cells with serum from normal rabbits and with serum from rabbits immunized with normal lactating mouse breast tissue.

INHIBITION OF MAMMARY GROWTH BY LARGE AMOUNTS OF ESTROGEN1

THE MAMMARY GLANDS of male or immature female animals of several species develop when estrogeas-certain other sex hormones or chemically related substances are injected Equate amounts (1). In some species the breasts may undergo complete development during periods of treatment with adequate amounts of estrogen alone, for example, guinea pigs (2) and monkeys (3). The addition of progesterone was required for complete mammary growth in other species (4). The glands of animals of the latter group developed only a system of mammary ducts when estrogens were injected; the dev nt of the alveoli depended upon the administration of progesterone. The administration of large amount estrogen to mice for long periods resulted in abnormal and stunted mammary glands (5). Similar observations have been made in rats (6). The restricted growth of the breast tissues of mice receiving large amounts of several estrogens was apparent within 15 days after the injections were started (7).