Autoradiographic studies on proliferation of epithelial cells in the mammary glands of white mice during lactation
Teppa-Szumowska, E.
Folia Morphologica 33(2): 197-204
1974
ISSN/ISBN: 0015-5659 PMID: 4546734 Document Number: 82826
Slices of mammary glands were obtained from 36 white mice which had been injected with [14C]thymidine and subsequently killed on day 1, 3, 6, 10 or 15 of lactation. Proliferation of epithelial cells, estimated as % cell nuclei labelled with thymidine, was highest on 1st day of lactation both in (i) secretory vesicles + intralobular efferent ducts (10.8%) and in (ii) the interlobular efferent ducts (6%). Significant decreases in these values were observed by day 6 of lactation, to 2.5% in (i) and to 2.2% in (ii). Level of proliferation of epithelial cells in connective tissue (control tissue) was only 0.7%. Possible influence of hormone levels and increased DNA synthesis in the mammary gland during lactation on degree of proliferation of epithelial cells is discussed.