| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
Regular Article |
a University of Washington School of Fisheries, Seattle, Washington 98192
b Northwest Fisheries Science Center, Seattle, Washington 98112
ABSTRACT
The effects of insulin-like growth factor I (IGF-I) and insulin on the function of coho salmon gonadotropes in vitro were investigated. Dispersed pituitary cells from immature coho salmon (Oncorhynchus kisutch) were incubated with IGF-I for 1, 3, 7, or 10 days, then incubated with salmon GnRH for an additional 24 h. Medium FSH content before and after GnRH treatment and intracellular FSH content after GnRH treatment were measured. Incubation of pituitary cells with IGF-I for 7 or 10 days increased GnRH-stimulated FSH release and remaining cell content, but did not affect basal release. To examine the specificity of the effects of IGF-I, we compared FSH release and cell content of FSH and LH after 10-day incubation with a range of concentrations of IGF-I or insulin. Incubation with physiological concentrations of IGF-I resulted in significantly higher GnRH-stimulated FSH release and remaining cell content of FSH and LH. Conversely, supraphysiological concentrations of insulin were required to produce more moderate effects on gonadotropin levels. These results suggest that elevation of gonadotropin levels by IGF-I may be one mechanism by which somatic growth and nutrition promote pubertal development in salmon.
First decision: 9 January 2000.
1 This work was supported by Bonneville Power Administration (Projects 92-022 and 93-056) and by the Joint Institute for the Study of the Atmosphere and Ocean under National Oceanic and Atmospheric Administration cooperative agreement NA67RJO155, contribution 758. D.M.B. was supported in part by the H. Mason Keeler Fellowship of the University of Washington School of Fisheries.
2 Correspondence: Dianne M. Baker, University of Washington School of Fisheries, Box 355020, Seattle, WA 98195. FAX: 206 860 3267; dibaker{at}u.washington.edu
This article has been cited by other articles:
|
|
 |
|
  B. Campbell, J. Dickey, B. Beckman, G. Young, A. Pierce, H. Fukada, and P. Swanson Previtellogenic Oocyte Growth in Salmon: Relationships among Body Growth, Plasma Insulin-Like Growth Factor-1, Estradiol-17beta, Follicle-Stimulating Hormone and Expression of Ovarian Genes for Insulin-Like Growth Factors, Steroidogenic-Acute Regulatory Protein and Receptors for Gonadotropins, Growth Hormone, and Somatolactin Biol Reprod, July 1, 2006; 75(1): 34 - 44. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 L. Huo, G. Fu, X. Wang, W. K. W. Ko, and A. O. L. Wong Modulation of Calmodulin Gene Expression as a Novel Mechanism for Growth Hormone Feedback Control by Insulin-like Growth Factor in Grass Carp Pituitary Cells Endocrinology, September 1, 2005; 146(9): 3821 - 3835. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 A. Rose, P. Froment, V. Perrot, M. J. Quon, D. LeRoith, and J. Dupont The Luteinizing Hormone-releasing Hormone Inhibits the Anti-apoptotic Activity of Insulin-like Growth Factor-1 in Pituitary {alpha}T3 Cells by Protein Kinase C{alpha}-mediated Negative Regulation of Akt J. Biol. Chem., December 10, 2004; 279(50): 52500 - 52516. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
B. Campbell, J.T. Dickey, and P. Swanson Endocrine Changes During Onset of Puberty in Male Spring Chinook Salmon, Oncorhynchus tshawytscha Biol Reprod, December 1, 2003; 69(6): 2109 - 2117. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
