Normal and Experimental Involution of Rat Mammary Gland. ∗

Abstract

Summary

With DNA as a measure of mammary gland involution, a 42% decrease in DNA between day 1 of lactation and day 5 of involution was noted. By day 10, DNA decreased 85% and remained essentially constant throughout the remainder of the period. E alone appeared to augment retrogression of DNA during initial days of involution, but with E + P this effect was not apparent. With both E and E + P, mammary gland DNA was increased during the later days of experimental period.