Abstract
Treatment of sham-operated female silver eels with carp pituitary extract stimulated ovarian development and induced increases in pituitary gonadotropin (GTH) and gonadoliberin (GnRH) contents. Both effects of carp pituitary extract were abolished in ovariectomized eels, indicating the involvement of the gonads. Endogenous sexual steroids, the secretion of which was increased during sexual maturation, should be responsible for the stimulation of GTH and GnRH levels. Ovariectomy itself had no significant effect on pituitary GTH and GnRH contents, reflecting the fact that, at the silver stage, sexual steroid levels are too low to exert any significant effect on pituitary GTH and GnRH. The positive feedback control exerted by the gonads on GTH and GnRH levels during sexual maturation, in the eel as well as in some other teleosts, would produce an amplification of the pubertal stimulation of the hypothalamo-pituitary-gonadal axis.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References cited
Burzawa-Gérard, E. 1971. Purification d'une hormone gonadotrope hypophysaire de poisson téléostéen, la carpe (Cyprinus carpio L.). Biochim. 53: 545–552.
Burzawa-Gérard, E. 1982. Chemical data on pituitary gonadotropins and their implication to evolution. Can. J. Fish. Aquat. Sci. 39: 80–91.
Burzawa-Gérard, E. and Kerdelhué, B. 1978. Étude par radioimmunologie des propriétés des immunsérums de l'hormone gonadotrope de la carpe (Cyprinus carpio). Ann. Biol. Anim. Biochem. Biophys. 18: 773–780.
Counis, R., Dufour, S., Ribot, G., Querat, B., Fontaine, Y.A. and Jutisz, M. 1987. Estradiol has inverse effects on pituitary glycoproteic hormone alpha-subunit messenger ribonucleic acid in the immature european eel and gonadectomized rat. Endocrinology 121: 1178–1184.
Crim, L.W., Billard, R., Genge, P.D. and Idler, D.R. 1982. The influence of immature gonads on onset of gonadotropic hormone accumulation in the juvenile rainbow trout pituitary gland. Gen. Comp. Endocrinol. 48: 161–166.
Dufour, S. 1985. La fonction gonadotrope de l'anguille européenne,Anguilla anguilla L., au stade argenté (au moment du départ pour la migration de réproduction): les mécanismes de son blocage et sa stimulation expérimentale. Sci. D. Thésis, Université Paris 6, France.
Dufour, S. 1986. La Saga des anguilles. La Recherche 182: 1456–1459.
Dufour, S., Pasqualini, C., Kerdelhue, B. and Fontaine, Y.A. 1982. Presence and distribution of radioimmunoassayable LHRH in the European eel,Anguilla anguilla. Neuropept. 3: 159–171.
Dufour, S., Delerue-Le Belle, N. and Fontaine, Y.A. 1983a. Development of a heterologous radioimmunoassay for eel (Anguilla anguilla) gonadotropin. Gen. Comp. Endocrinol. 49: 404–413.
Dufour, S., Delerue-Le Belle, N. and Fontaine, Y.A. 1983b. Effects of steroid hormones on pituitary immunoreactive gonadotropin in European freshwater eel,Anguilla anguilla L. Gen. Comp. Endocrinol. 52: 190–197.
Dufour, S., Fontaine, Y.A. and Kerdelhué, B. 1985. Increase in brain and pituitary radioimmunoassayable gonadotropin releasing hormone (GnRH) in the European silver eel treated with sexual steroid or human chorionic gonadotropin. Neuropept. 6: 495–502.
Dufour, S., Lopez, E., Le Menn, F., Le Belle, N., Baloche, S. and Fontaine, Y.A. 1988. Stimulation of gonadotropin release and of ovarian development, by the administration of a gonadoliberin agonist and of dopamine antagonists, in female silver eel pretreated with estradiol. Gen. Comp. Endocrinol. 70: 20–30.
Fahreus-Van Ree, G.E. Guldenaar, S.E.F. and Gielen, J.Th. 1982. Fine structure and fonction of isolated gonadotropic cells as revealed from pituitaries of immature rainbow trout,Salmo gairdneri, by means of a new enzymatic dispersion technique. Cell Tiss. Res. 226: 641–653.
Gielen, J.Th., Goos, H.J.Th., Peute, J., Van den Bosch, R.A. and Van Oordt, P.G.W.J. 1982. The brain-pituitary-gonadal axis in the rainbow trout,Salmo gairdneri: gonadal hormones and the maturation of gonadotropic cells. Cell Tiss. Res. 225: 45–56.
Goos, H.J.Th. 1987. Steroid feedback on gonadotropin secretion.In Proc. Third Int. Symp. Reprod. Physiol. Fish. pp. 16–20. Edited by D.R. Idler, L.W. Crim and J.M. Walsh. Memorial University Press, St. John's.
Goos, H.J.Th., De Leeuw, R., Cook, H. and Van Oordt, P.G.W.J. 1986. Gonadotropic hormone-releasing hormone (GnRH) bioactivity in the brain of immature rainbow trout,Salmo gairdneri: the effect of testosterone. Gen. Comp. Endocrinol. 64: 80–84.
Kah, O., Dufour, S., Baloche, S. and Breton, B. 1988. Immunocytochemical study of GnRH systems in the brain and pituitary of normal and hCG treated European eels.In Reproduction in Fish, Basic and Applied Aspects in Endocrinology and Genetics. Edited by Les Colloques de l'INRA, Paris (In press).
Kalra, P.S. 1985. Stimulation of hypothalamic LHRH levels and release by gonadal steroids. J. Ster. Biochem. 23: 725–731.
Khan, I.A., Lopez, E. and Leloup-Hatey, J. 1987. Induction of spermatogenesis and spermiation by a single injection of human chorionic gonadotropin in intact and hypophysectomized European eel (Anguilla anguilla L.). Gen. Comp. Endocrinol. 68: 91–103.
Landefeld, T. and Kepa, J. 1984. Regulation of LH beta mRNA in the sheep pituitary gland during different feedback states of estradiol. Biochem. Biophys. Res. Commun. 122: 1307–1313.
Leloup-Hatey, J., Hardy, A., Nahoul, K., Querat, B. and Zohar, Y. 1988. Influence of a gonadotropic treatment upon the ovarian steroidogenesis in European silver eel (Anguilla anguilla L.).In Reproduction in Fish, Basic and Applied Aspects in Endocrinology and Genetics. Edited by Colloques de l'INRA, Paris. (In press).
Melrose, P. and Gross, L. 1987. Steroid effects on the secretory modalities of gonadotropin-releasing hormone release. Endocrinology 121: 190–199.
Olivereau, M. and Chambolle, P. 1978. Ultrastructure des cellules gonadotropes de l'anguille normale et après injection d'oestradiol. C.R. Acad. Sci. Paris, Ser. D. 287: 1409–1412.
Pattriti-Laborde, N. and Odell, W.D. 1981. Effects of alpha- and beta-hCG subunits on the shortloop feedback control of gonadotropins. Neuroendocrinology 33: 257–260.
Salacinski, P.R.P., McLean, C., Sykes, J.E.C., Clement-Jones, U.U. and Lowry, P.J. 1981. Iodination of proteins, glycoproteins, and peptides using a solid-phase oxidizing agent, 1,3,4,6-tetrachloro-3-6 diphenyl glycoluryl (Iodogen). Anal. Biochem. 117: 136–146.
Schreibman, M.P., Margolis-Nunno, H., Halpern-Sebold, L., Goos, H.J.Th. and Perlman, P.W. 1986. The influence of androgen administration on the structure and function of the brain-pituitary-gonad axis of sexually immature platyfish,Xyphophorus maculatus. Cell. Tiss. Res. 245: 519–524.
Trinh, K.Y., Wang, N.C., Hew, C.L. and Crim, L.W. 1986. Molecular cloning and sequencing of salmon gonadotropin beta subunit. Eur. J. Biochem. 159: 619–624.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Dufour, S., Le Belle, N., Baloche, S. et al. Positive feedback control by the gonads on gonadotropin (GTH) and gonadoliberin (GnRH) levels in experimentally matured female silver eels,Anguilla anguilla . Fish Physiol Biochem 7, 157–162 (1989). https://doi.org/10.1007/BF00004702
Issue Date:
DOI: https://doi.org/10.1007/BF00004702