Effects of sustained administration of testosterone in pre-pubertal sea bass (Dicentrarchus labrax L)

Zanuy, Silvia; Carrillo, Manuel; Mateos, Jorge; Trudeau, Vance L.; Kah, Olivier

doi:10.1016/s0044-8486(99)00066-6

Cited by 43 publications

(20 citation statements)

References 33 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The histological examination of testes in the present study revealed severe effects on the testicular structure in response to exposure to EE 2 and wastewater effluent. Similar findings (i.e., accelerated gonadal differentiation and, to some extent, stimulated spermatogenesis) also have been reported after implantation of testosterone into juvenile sea bass (Dicentranchus labrax) [38]. Similar effects have been shown with estrogenic exposure in other teleosts [34][35][36].…”

Section: Histopathologysupporting

confidence: 82%

Estrogenic and androgenic effects of municipal wastewater effluent on reproductive endpoint biomarkers in three‐spined stickleback (Gasterosteus aculeatus)

Björkblom

Salste

et al. 2009

Enviro Toxic and Chemistry

View full text Add to dashboard Cite

Municipal wastewater treatment plants have been associated with the release of endocrine-disrupting chemicals, which consequently lead to alterations of reproductive function in aquatic organisms. The three-spined stickleback (Gasterosteus aculeatus) has quantifiable biomarkers for assessment of both estrogen (vitellogenin) and androgen (spiggin) activity, which makes this species very valuable in the research of endocrine disruption. The estrogenic and androgenic biomarkers were used for evaluating exposure effects of municipal wastewater effluent. We evaluated the effects of 17alpha-ethinylestradiol (EE2), 17alpha-methyltestosterone (MT), and wastewater effluents on induction of vitellogenin and spiggin production, gonadosomatic index, hepatosomatic index, nephrosomatic index, plasma steroid levels, and histopathology. Adult female and male sticklebacks were exposed to 20 ng/L of EE2, 10 microg/L of MT, and wastewater effluent (10, 50, and 80% of original concentration) in a flow-through system for an exposure of one week and an extended exposure of four weeks. Chemical analyses of the steroids were done for verification of exposure concentrations and presence in the used wastewater. Our results show that municipal wastewater effluent exerts estrogenic action on three-spined stickleback as observed by elevated vitellogenin levels in exposed fish, corresponding to the effect seen in fish exposed to EE2. Furthermore, wastewater and EE2 exerted similar histopathological effects on testis of exposed fish. Although domestic effluent is suspected to have a high content of natural androgens, no obvious androgenic effect of wastewater was observed in the present study.

show abstract

Section: Histopathologysupporting

confidence: 82%

Estrogenic and androgenic effects of municipal wastewater effluent on reproductive endpoint biomarkers in three‐spined stickleback (Gasterosteus aculeatus)

Björkblom

Salste

et al. 2009

Enviro Toxic and Chemistry

View full text Add to dashboard Cite

show abstract

“…It has been suggested that E 2 may induce spermatogonial renewal from stem cells (Schulz & Miura, 2002). Basal levels of E 2 were also detected in earlier studies of male European sea bass (Zanuy et al ., 1999).…”

Section: Discussionmentioning

confidence: 99%

Growth, sex differentiation and gonad and plasma levels of sex steroids in male‐ and female‐dominant populations of Dicentrarchus labrax obtained through repeated size grading

Papadaki

Piferrer

Zanuy

et al. 2005

Journal of Fish Biology

View full text Add to dashboard Cite

Starting from 66 days post hatching (dph), European sea bass Dicentrarchus labrax were graded successively to create a fast growing (L-extreme) and a slow growing (S-extreme) population. The L-extreme population grew significantly larger (ANOVA, n ¼ 89-101, P < 0Á01) attaining twice the wet mass of the S-extreme population at 300 dph (130Á9 AE 1Á8 v. 66Á7 AE 0Á9 g, mean S.E.). When the two populations were sexed, the L-extreme consisted of 96Á5% and the Sextreme of 30Á2% females, while the ungraded control had 59Á2% females. Sex differentiation began first in females at a total length (L T ) of 97 AE 4 mm and wet mass of 9Á4 AE 1Á2 g (150 dph), and was completed when fish reached 166 AE 6 mm and 53Á4 AE 6Á4 g (250 dph) in both sexes. Precocious maturation in males was positively correlated to growth. Gonad oestradiol (E 2 ) was significantly higher in the female-dominant population at the onset of ovarian differentiation (ANOVA, n ¼ 10, P < 0Á05) and in the plasma after the appearance of the first primary oocytes (P < 0Á01). Gonad testosterone (T) increased in both populations after sex differentiation (ANOVA, n ¼ 10, P < 0Á05), while plasma levels were significantly higher in the male-dominant population (P < 0Á001). Both gonad and plasma 11-keto testosterone (11-KT) were significantly higher in the male-dominant population (ANOVA, n ¼ 10, P < 0Á01) reaching maximal values at spermiation. The results suggest that E 2 is closely related with ovarian differentiation and the onset of oogenesis, while T and 11-KT is more related to spermatogenesis and precocious maturation. # 2005 The Fisheries Society of the British Isles

show abstract

“…Nevertheless, it is well established that hormonal intervention can induce spermatogenesis, overriding the genetic basis of puberty [24][25][26][27]. The mechanism involved in the differentiation of 2-yrold striped bass into maturing males was investigated in two experiments.…”

Section: Introductionmentioning

confidence: 99%

Early Maturity in the Male Striped Bass, Morone saxatilis: Follicle-Stimulating Hormone and Luteinizing Hormone Gene Expression and Their Regulation by Gonadotropin-Releasing Hormone Analogue and Testosterone1

Hassin

Holland

Zohar

2000

Biology of Reproduction

View full text Add to dashboard Cite

Striped bass are seasonal breeding fish, spawning once a year during the spring. All 3-yr-old males are sexually mature; however, 60-64% of the fish mature earlier as 1- or 2-yr-old animals. The endocrine basis underlying early maturity in 2-yr-old males was studied at the molecular level by monitoring changes in pituitary beta FSH and beta LH mRNA levels by ribonuclease protection assay, and correlating these changes to stages of testicular development. In maturing males, the mRNA levels of beta FSH were elevated during early spermatogenesis, whereas beta LH mRNA levels peaked during spermiation. The appearance of spermatozoa in the testis was associated with a decrease in beta FSH mRNA and a rise in beta LH mRNA abundance. Immature males had lower levels of beta LH mRNA than maturing males, but there were no differences in beta FSH mRNA levels between immature and maturing males. The regulation of gonadotropin gene expression in 2-yr-old males was studied by the chronic administration of GnRH analogue (GnRHa) and testosterone (T), with or without pimozide (P) supplementation. In immature males, the combination of T and GnRHa stimulated a three- to fivefold increase in beta FSH and beta LH mRNA levels, but the same treatment had no effect on gonadotropin gene expression in maturing males. In addition, the coadministration of P to immature males suppressed the stimulatory effect of GnRHa and T on beta FSH and beta LH mRNA levels, suggesting that dopamine may have a novel role in regulating gonadotropin gene expression.

show abstract

Effects of sustained administration of testosterone in pre-pubertal sea bass (Dicentrarchus labrax L)

Cited by 43 publications

References 33 publications

Estrogenic and androgenic effects of municipal wastewater effluent on reproductive endpoint biomarkers in three‐spined stickleback (Gasterosteus aculeatus)

Estrogenic and androgenic effects of municipal wastewater effluent on reproductive endpoint biomarkers in three‐spined stickleback (Gasterosteus aculeatus)

Growth, sex differentiation and gonad and plasma levels of sex steroids in male‐ and female‐dominant populations of Dicentrarchus labrax obtained through repeated size grading

Early Maturity in the Male Striped Bass, Morone saxatilis: Follicle-Stimulating Hormone and Luteinizing Hormone Gene Expression and Their Regulation by Gonadotropin-Releasing Hormone Analogue and Testosterone1

Contact Info

Product

Resources

About