[Pregna-D'-pentaranes, progestins, and antiprogestins: II. Pathways and realization mechanisms of separate biological functions of steroid hormones].

The manner in which multifunctional steroid hormones realize their separate biological functions in mammal organisms is considered. This study is carried out on the basis of a systematic set of progesterone analogues, which we developed and described in part I of the review. This set has for the first time enabled the use of compounds of this type for studying the pathways and realization mechanisms of separate biological functions of steroid hormones. The interaction of pregna-D'-pentaranes with the classical progesterone receptor, their independent influence on the myometrium and ovogenesis, and some nonclassical effects are described. A scheme of realization is suggested for the biological functions already known, newly discovered, and presumed by us that, during pregnancy, are fulfilled in mammal organisms by progesterone and its nearest metabolite, dihydroprogesterone. The English version of the paper: Russian Journal of Bioorganic Chemistry, 2005, vol. 31, no. 3; see also http://www.maik.ru.