Role of 5α-dihydrotestosterone in testicular development of gilthead seabream following finasteride administration

•T serum levels regulate DHT serum levels by down-regulating the transcript levels of srd5a.•DHT triggers the onset of the meiotic phase of spermatogenesis.•DHT is involved in the regulation of E2 serum levels. In teleosts, spermatogenesis is regulated by pituitary gonadotropins and sex steroids. 5α...

Full description

Saved in:
Bibliographic Details
Published in:The Journal of steroid biochemistry and molecular biology 2017-11, Vol.174, p.48-55
Main Authors: García-García, M., Sánchez-Hernández, M., García-Hernández, M.P., García-Ayala, A., Chaves-Pozo, E.
Format: Article
Language:English
Subjects:
11-beta-Hydroxysteroid Dehydrogenase Type 1 - genetics
3-Oxo-5-alpha-Steroid 4-Dehydrogenase - genetics
5-alpha Reductase Inhibitors - pharmacology
5α-Reductase
Androgens - blood
Androgens - pharmacology
Animals
Aromatase - genetics
Dihydrotestosterone - blood
Estradiol - blood
Finasteride - pharmacology
Fish Proteins - genetics
Male
Sea Bream
Sex steroids
Sparus aurata
Steroid 11-beta-Hydroxylase - genetics
Steroidogenic enzyme inhibitors
Testis - drug effects
Testis - growth & development
Testosterone - analogs & derivatives
Testosterone - blood
Testosterone - pharmacology
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:•T serum levels regulate DHT serum levels by down-regulating the transcript levels of srd5a.•DHT triggers the onset of the meiotic phase of spermatogenesis.•DHT is involved in the regulation of E2 serum levels. In teleosts, spermatogenesis is regulated by pituitary gonadotropins and sex steroids. 5α-dihydrotestosterone (DHT), derived from testosterone (T) through the action of 5α-reductase, has recently been suggested to play a physiologically important role in some fish species. In this study, gilthead seabream, Sparus aurata L., males received an implant of 1μgT/g body mass (bm) or vehicle alone and, 7days later, 1mg finasteride (FIN, an inhibitor of 5α-reductase)/kg bm or vehicle. Serum levels of T, 11-ketotestosterone (11KT), DHT and 17β-estradiol (E2), and the mRNA levels of the main enzymes involved in their synthesis, were analysed. T promoted a transient increase in the serum levels of T, 11KT and E2 but a decrease in those of DHT at day 15 following T injection, in accordance with the up-regulation of mRNA levels of the enzymes involved in T transformation to 11KT (coding genes: cyp11b1 and hsd11b) and the down-regulation of mRNA levels of the enzyme responsible for T transformation to DHT (coding gene: srd5a). Interestingly, a similar effect was observed when FIN was injected. However, when fish were injected with T and FIN successively (T+FIN), control levels were not recovered at the end of the experimental period (28days). DHT seems to regulate E2 serum levels via the down-regulation of mRNA levels of aromatase (coding gene: cyp19a1a), which is needed for the transformation of T into E2. The testis histology, together with the proliferative rates recorded upon T, FIN or T+FIN treatment, suggests that DHT is involved in the onset of the meiotic phase of spermatogenesis.
ISSN:0960-0760
1879-1220
DOI:10.1016/j.jsbmb.2017.07.024