[Lotus]

The pathways of progesterone action in target tissues are not well defined and, in many respects, distinctions remain to be made between the direct downstream targets of progesterone action and indirect consequences of progesterone regulation. Furthermore, as the effects of progesterone are mediated by its receptor and as PR is induced by estrogen in most target tissues, the delineation of specific progesterone effects, as distinct from those of estrogen, is similarly not clear. A number of reviews have described the molecular mechanisms of PR action (2, 3, 4), progesterone and progesterone antagonist effects on cellular proliferation (5, 6), and regulation of the concentration of progesterone-responsive proteins (7, 8). This review does not seek to replicate existing reviews of the molecular biology of PR action but will provide an overview of the physiological action of progesterone and its regulation of gene expression in target tissues.

Physiological Action of Progesterone in Target Tissues
http://press.endocrine.org/doi/full/10.1210/edrv.18.4.0308