<b>CELL PROLIFERATION IN THE ANTERIOR PITUITARY OF MICE DURING </b><b>GROWTH </b>

Abstract

Proliferative activity of the anterior pituitary cells in 2, 8, 15, 22 and 60-day-old mice was investigated by the use of a recently developed labelling method whereby bromodeoxyuridine (BrDU) incorporated into DNA is detected immunohistochemically using a monoclonal antibody. The anterior pituitaries were examined 3 h after BrDU injection. The number of BrDU-labelled cells/mmz of the anterior pituitary was greatest at 8 days. Labelling occurred less frequently at l5 and 22 days and was the lowest at 60 days of age. In most cases, BrDU-labelled cells were distributed homogeneously throughout the anterior pituitary. Immunoreactive cells, however, were occasionally concentrated in the marginal layer of the adenohypophysis at 2 days. To know the extent of the proliferative rate of already dilferentiated