title: Foetal Leydig cells and the neuroendocrine system.
abstract: It has been shown that adult human Leydig cells express a number of neuroendocrine markers, and, therefore, could be considered as a part of the neuroendocrine system in the adult. A limited number of studies have dealt with the dynamics of development of human foetal Leydig cells, whereas studies on their neuroendocrine nature are still extremely rare. Therefore, the aim of our study was to investigate the development of human foetal Leydig cells in different weeks of gestation (wg) and to check if these cells express certain markers characteristic of the diffuse neuroendocrine system (DNS). Qualitative, quantitative histological studies and immunohistochemical analyses of human foetal testicular tissue have been performed. According to our data, Leydig cells formed a dynamic population of cells within the interstitum of testes in the period between 15 and 36 wg. The total number of Leydig cells of human foetal testes changed through different stages of gestation by means of 'pulsatile' dynamics (most likely, by following the variable level of gonadotropins). At early stages of development (15-17 wg) immunohistochemical reactions for the expression of neuron specific enolase (NSE) were positive within sex cords and between them, in the interstitum. Pro-spermatogonia in the sex cords were positive, as well as elongated spindle-shaped cells of the interstitum (very likely, precursors of Leydig cells). During the later stages of development (28-36 wg), excluding the pro-spermatogonia, the interstitial Leydig cells were also positive. The results of the immunohistochemical analyses (the expression of NSE) confirmed the hypothesis that human foetal Leydig cells were of neuroendocrine nature.
authors.affiliation: Department of Neurology, General Hospital Bjelovar, Bjelovar, Croatia.
authors.forename: Duska
authors.initials: D
authors.lastname: Sklebar
authors.forename: Kristina
authors.initials: K
authors.lastname: Semanjski
authors.forename: Marina
authors.initials: M
authors.lastname: Kos
authors.forename: Ivan
authors.initials: I
authors.lastname: Sklebar
authors.forename: Davor
authors.initials: D
authors.lastname: Jezek
mesh_terms: D047109:Fetal Development / Q000502:physiology*; D005865:Gestational Age; D006801:Humans; D007985:Leydig Cells / Q000502:physiology* / Q000648:ultrastructure; D008297:Male; D009490:Neurosecretory Systems / Q000196:embryology / Q000254:growth & development / Q000502:physiology*; D010751:Phosphopyruvate Hydratase / Q000502:physiology
chemical_list: D010751:Phosphopyruvate Hydratase