[Chemotactic factor for spermatozoa: a new biological function of progesterone].

Our group has recently described the existence of a chemoattractant factor for spermatozoa contained in the mature follicles fluid. Simultaneously it was possible to develop a new method that permits to evaluate the chemotactic capacity of spermatozoa and that due to its simplicity makes possible the systematic study of CFS features. This study considered CFS molecular characterization from follicular fluid (FF). The FF of women was studied in an Assisted Fertilization Program, that were qualified as mature according to different criteria. The FF were fractioned with different techniques that permitted to separate an active fraction with lipid physicochemical characteristics. The fine layer chromatography showed the presence of different steroids, that were individually assayed for chemotactic activity. Only progesterone showed that activity and its effect showed a dose-response curve within physiological values. Our study permitted to identify progesterone as CFS previously described. This steroid's function is rather new and its action mechanism is being studied in our laboratory.