DNA Synthesis in Alveolar Cells of the Mammary Gland: Acceleration by Ovarian Hormones

Science  30 Oct 1964:
Vol. 146, Issue 3644, pp. 653-655
DOI: 10.1126/science.146.3644.653


In normal alveolar cells of the mammary gland of C3H/HeJ female mice, DNA synthesis lasts an average of 20.7 hours with a coefficient of variation of 26.6 percent. Treatment of the mice with I microgram of 17-β-estradiol and 1 milligram of progesterone per day for 3 to 4 days decreases the average duration to 10.7 hours and the coefficient of variation to 13.8 percent.