Free histones in the cells of the rat uterus after neonatal treatment with diethylstilbestrol or allylestrenol.

Neonatal diethylstilbestrol and allylestrenol treatments resulted in a prompt release of free histones that could be demonstrated histochemically by the phosphomolybdic-acid-benzidine reaction. This effect could not be observed in the uterus of 6-10-week old rats but reappeared between 11-14 weeks in the myometrium and uterine epithelium without any repeated treatment. This may be due to the increased production of endogenous steroids. The finding suggest caution when applying steroids to pregnants and neonates.