Hormonal regulation of rat uterine collagenase

Two different methods of study have been employed in the analysis of the hormonal regulation of rat uterine collagenases. The first is concerned with the enzyme activity and the second, its synthesis. The data presented in this report reveal that the rat uterine collagenase is under the regulatory influence of both estradiol and progesterone. This fact is first exemplified by the observation that on Day 2 post-ovriectomy, a wave of collagenase synthesis takes place which influences the enzyme activity in the uterus during the next 3-4 days. This peak in collagenase synthesis disappeared in the uteri of rats subjected to ovariectomy and adrenalectomy simultaneously. It indicated that a hormone of adrenal origin was responsible for the enhanced synthesis and activity of collagenase in the uteri of ovariectomized rats. That the hormone involved was progesterone was shown by the subsequent experimental data. The estradiol-mediated enhancement in rat uterine collagenase activity has been shown to be inhibited by intraluminal exposure of the uteri to actinomycin D/cyclohexinmide, indicating the apparent influence of the hormone at the level of the collagenase gene.