title: Androgen and oestrogen modulation by D-aspartate in rat epididymis.
abstract: Testosterone (T) synthesised in Leydig cells enters the epididymis and may there be converted into dihydrotestosterone (DHT) by 5α-reductase (5α-red) or into 17β-oestradiol (E2) by P450 aromatase (P450-aro). D-aspartate (D-Asp) is known to induce T synthesis in the testis. In this study, we investigated the effects of in vivo D-Asp administration in two major regions of the rat epididymis (Region I: initial segment, caput, corpus; Region II: cauda). The results suggest that exogenous D-Asp was taken up by both regions of rat epididymis. D-Asp administration induced a rapid increase in T, followed by a more gradual decrease in the T:DHT ratio in Region I. In Region II, T levels rapidly decreased and the T:DHT ratio was consistently lower relative to the control. Expression of 5α-red and androgen receptor genes showed a good correlation with DHT levels in both regions. D-Asp treatment also induced an increase of both E2 levels and oestradiol receptor-α (ERα) expression in Region I, whereas neither E2 levels nor ERα expression were affected in Region II. The early increase of P450-aro expression in Region I and late increase in Region II suggests a direct involvement of D-Asp modulation in P450-aro gene expression. Our results suggest that D-Asp modulates androgen and oestrogen levels and expression of androgen and oestrogen receptors in the rat epididymis by acting on the expression of 5α-red and P450-aro genes.
authors.affiliation: Dipartimento di Scienze e Tecnologie Ambientali, Biologiche e Farmaceutiche, Seconda Università di Napoli, Via Vivaldi 43, 81100, Caserta, Italy.
authors.forename: S
authors.initials: S
authors.lastname: Falvo
authors.affiliation: Dipartimento di Scienze e Tecnologie Ambientali, Biologiche e Farmaceutiche, Seconda Università di Napoli, Via Vivaldi 43, 81100, Caserta, Italy.
authors.forename: M M
authors.initials: MM
authors.lastname: Di Fiore
authors.affiliation: Dipartimento di Scienze e Tecnologie Ambientali, Biologiche e Farmaceutiche, Seconda Università di Napoli, Via Vivaldi 43, 81100, Caserta, Italy.
authors.forename: L
authors.initials: L
authors.lastname: Burrone
authors.affiliation: Dipartimento di Scienze e Tecnologie Ambientali, Biologiche e Farmaceutiche, Seconda Università di Napoli, Via Vivaldi 43, 81100, Caserta, Italy.
authors.forename: G Chieffi
authors.initials: GC
authors.lastname: Baccari
authors.affiliation: Medical Liaison Office, Merck Serono S.p.A., Via Casilina 125, 00176, Roma, Italy.
authors.forename: S
authors.initials: S
authors.lastname: Longobardi
authors.affiliation: Dipartimento di Scienze e Tecnologie Ambientali, Biologiche e Farmaceutiche, Seconda Università di Napoli, Via Vivaldi 43, 81100, Caserta, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Santillo
mesh_terms: D013741:3-Oxo-5-alpha-Steroid 4-Dehydrogenase / Q000378:metabolism; D000818:Animals; D001141:Aromatase / Q000378:metabolism; D026603:D-Aspartic Acid / Q000494:pharmacology*; D013196:Dihydrotestosterone / Q000378:metabolism*; D004822:Epididymis / Q000187:drug effects* / Q000502:physiology; D004958:Estradiol / Q000378:metabolism; D004967:Estrogens / Q000378:metabolism*; D008297:Male; D051381:Rats; D011944:Receptors, Androgen / Q000378:metabolism; D013739:Testosterone / Q000378:metabolism*
chemical_list: D004967:Estrogens; D011944:Receptors, Androgen; D013196:Dihydrotestosterone; D013739:Testosterone; D026603:D-Aspartic Acid; D004958:Estradiol; D001141:Aromatase; D013741:3-Oxo-5-alpha-Steroid 4-Dehydrogenase