Differential Effect of Insulin-Like Growth Factor I on in Vitro Gonadotropin (I and II) and Growth Hormone Secretions in Rainbow Trout (Oncorhynchus mykiss) at Different Stages of the Reproductive Cycle.

The short-term effect of insulin-like growth factor I (IGF-I) on GTH I (FSH-like), GTH II (LH-like), and GH production by cultured rainbow trout pituitary cells was studied in immature fish of both sexes, at early gametogenesis and in spermiating and periovulatory animals. IGF-I had no effect on basal GTH I and GTH II release, whereas it always inhibited basal GH, showing decreasing intensity with the gonad maturation. In absence of IGF-I, GTH I and GTH II cells were always responsive to GnRH, whereas no response was observed for GH cells whatever the sexual stage. The action of IGF-I on the sensitivity to GnRH differs between GTH and GH cells. The former requires a coincubation with IGF−I (10−6 m)/GnRH to show an increase in sensitivity, independent of the sexual stage. To be responsive to GnRH, the GH cells require longer exposure to IGF-I, the efficiency of which decreases with gonad maturation. The action of IGF-I (10−6 m) on GTH cell sensitivity to GnRH does not seem to be related to a mitogenic effe...

[1]  M. Govoroun,et al.  Immunological Cross-Reactivity between Rainbow Trout GTH I and GTH II and Their α and β Subunits: Application to the Development of Specific Radioimmunoassays☆ , 1998 .

[2]  M. Govoroun,et al.  GTH I and GTH II secretion profiles during the reproductive cycle in female rainbow trout: relationship with pituitary responsiveness to GnRH-A stimulation. , 1998, General and comparative endocrinology.

[3]  P. Goff,et al.  Structure, Function, and Regulation of Insulin‐like Growth Factors in Fish , 1998, Annals of the New York Academy of Sciences.

[4]  S. Takeuchi,et al.  Stimulatory effect of insulin-like growth factor I on proliferation of mouse pituitary cells in serum-free culture. , 1998, The Journal of endocrinology.

[5]  J. Huet,et al.  Use of immobilized metal ion affinity chromatography and dye-ligand chromatography for the separation and purification of rainbow trout pituitary gonadotropins, GTH I and GTH II. , 1997, Journal of chromatography. B, Biomedical sciences and applications.

[6]  M. Maestro,et al.  Ovarian receptors for insulin and insulin-like growth factor I (IGF-I) and effects of IGF-I on steroid production by isolated follicular layers of the preovulatory coho salmon ovarian follicle. , 1997, General and comparative endocrinology.

[7]  C. Weil,et al.  Permissive Effect of Insulin-like Growth Factor I (IGF-I) on Gonadotropin Releasing-hormone Action on In Vitro Growth Hormone Release, in Rainbow Trout (Oncorhynchus mykiss) , 1997 .

[8]  S. Ojeda,et al.  Insulin-like growth factor I of peripheral origin acts centrally to accelerate the initiation of female puberty. , 1996, Endocrinology.

[9]  J. Sumpter,et al.  Validation of radioimmunoassays for two salmon gonadotropins (GTH I and GTH II) and their plasma concentrations throughout the reproductivecycle in male and female rainbow trout (Oncorhynchus mykiss). , 1996, Biology of reproduction.

[10]  A. Bartke,et al.  Effects of growth hormone on neuroendocrine function. , 1996, Acta neurobiologiae experimentalis.

[11]  S. Yen,et al.  Modulation of anterior pituitary luteinizing hormone response to gonadotropin-releasing hormone by insulin-like growth factor I in vitro. , 1995, Fertility and sterility.

[12]  C. Weil,et al.  Role of IGF-I in the control of GH secretion in rainbow trout (Oncorhynchus mykiss). , 1995, Growth regulation.

[13]  M. Maestro,et al.  Insulin and IGF-I binding and tyrosine kinase activity in fish heart. , 1995, The Journal of endocrinology.

[14]  C. Weil,et al.  Lack of gonadotropin releasing-hormone action on in vivo and in vitro growth hormone release, in rainbow trout (Oncorhynchus mykiss) , 1995 .

[15]  A. Cagnacci,et al.  Insulin, insulin-like growth factor I (IGF-I) and IGF-II enhance basal and gonadotrophin-releasing hormone-stimulated luteinizing hormone release from rat anterior pituitary cells in vitro. , 1994, European journal of endocrinology.

[16]  P. Stewart,et al.  Role of growth factors and estrogen as modulators of growth, differentiation, and expression of gonadotropin subunit genes in primary cultured sheep pituitary cells. , 1994, Endocrinology.

[17]  S. Duguay,et al.  Recombinant coho salmon insulin-like growth factor I. Expression in Escherichia coli, purification and characterization. , 1993, European journal of biochemistry.

[18]  E. Plisetskaya,et al.  Nutritional regulation of insulin-like growth factor-I mRNA expression in salmon tissues. , 1993, The Journal of endocrinology.

[19]  S. Duguay,et al.  Does salmon brain produce insulin? , 1993, General and comparative endocrinology.

[20]  S. Gammeltoft,et al.  Identification of IGF-1 receptors in primitive vertebrates , 1993, Regulatory Peptides.

[21]  C. Bondy,et al.  Anatomy of the pituitary insulin-like growth factor system. , 1992, Endocrinology.

[22]  T. T. Chen,et al.  Identification of a second insulin-like growth factor in a fish species. , 1992, Proceedings of the National Academy of Sciences of the United States of America.

[23]  C. Weil,et al.  Effects of human insulin-like growth factor-I on release of growth hormone by rainbow trout (Oncorhynchus mykiss) pituitary cells. , 1992, The Journal of experimental zoology.

[24]  K. Aida,et al.  Changes in Salmon GnRH and Chicken GnRH-II Contents in the Brain and Pituitary, and GTH Contents in the Pituitary in Female Masu Salmon, Oncorhynchus masou, from Hatching through Ovulation(Endocrinology) , 1992 .

[25]  M. Irahara,et al.  Effect of insulin-like growth factor I on gonadotropin release from the hypothalamus-pituitary axis in vitro. , 1991, Acta endocrinologica.

[26]  J. Sumpter,et al.  Development and validation of a highly sensitive radioimmunoassay for chinook salmon (Oncorhynchus tshawytscha) growth hormone. , 1991, General and comparative endocrinology.

[27]  E. Plisetskaya,et al.  Insulin binding to liver plasma membranes of coho salmon during smoltification. , 1991, General and comparative endocrinology.

[28]  M. Berelowitz,et al.  Pituitary insulin-like growth factor-I content and gene expression in the streptozotocin-diabetic rat: evidence for tissue-specific regulation. , 1991, Endocrinology.

[29]  T. Mommsen.  Insulin in fishes and agnathans:history, structure and metabolic regulation , 1991 .

[30]  S. Ojeda,et al.  Insulin-like growth factor I: a possible metabolic signal involved in the regulation of female puberty. , 1991, Neuroendocrinology.

[31]  D. Steiner,et al.  Nucleotide sequence and growth hormone-regulated expression of salmon insulin-like growth factor I mRNA. , 1989, Molecular endocrinology.

[32]  Rennes,et al.  Growth-reproduction interaction in Salmonids , 1988 .

[33]  L. Poretsky,et al.  The gonadotropic function of insulin. , 1987, Endocrine reviews.

[34]  F. Le Gac,et al.  Use of pituitary cells in primary culture to study the regulation of gonadotropin hormone (GtH) secretion in rainbow trout: setting up and validating the system as assessed by its responsiveness to mammalian and salmon gonadotropin releasing hormone. , 1986, General and comparative endocrinology.

[35]  B. Posner,et al.  Characterization of insulin-like growth factor receptors in rat anterior pituitary, hypothalamus, and brain. , 1984, Endocrinology.

[36]  Y. Zohar,et al.  7 The Gonadal Steroids , 1983 .

[37]  G. Rice.  Plasma arginine vasotocin concentrations in the lizard Varanus gouldii (Gray) following water loading, salt loading, and dehydration. , 1982, General and comparative endocrinology.

[38]  E. Adashi,et al.  Insulin enhancement of luteinizing hormone and follicle-stimulating hormone release by cultured pituitary cells. , 1981, Endocrinology.