title: [Embryonal development of interstitial Leydig cells in the rat testis].
abstract: Blood testosterone concentrations are not constant throughout life, there being a direct correlation with the numbers of cells producing that hormone, for which reason the existence of two Leydig's cells populations has been proposed: one foetal formation, which disappears just prior or immediately after birth, and a subsequent adult generation. In recent studies, however, that withdrawal has not been observed. Considering all the above, we have studied the evolution of these elements during the rat foetal period. From a morphological point of view Leydig's cells do not differentiate from those in the gonadal interstice until day 17 of pregnancy, showing a considerable increase in their numbers by day 21: while from that day onwards their numbers decrease they never disappear completely. We believe those cells become differentiated from the interstitial mesenchymal cells, and that their increase is facilitated by the proliferation of these same elements.
authors.affiliation: Departamento de Biología Celular y Anatomía Patológica, Universidad de Cádiz.
authors.forename: A
authors.initials: A
authors.lastname: López
authors.forename: A
authors.initials: A
authors.lastname: Quiros
authors.forename: A
authors.initials: A
authors.lastname: Ronco
authors.forename: J
authors.initials: J
authors.lastname: Castiñeiras
authors.forename: J
authors.initials: J
authors.lastname: Vilches
mesh_terms: D000818:Animals; D005865:Gestational Age; D007985:Leydig Cells; D008297:Male; D051381:Rats / Q000196:embryology*; D013737:Testis / Q000166:cytology* / Q000196:embryology*
vernacular_title: Desarrollo embrionario de las células intersticiales de Leydig en el testículo de rata.