Response of the somatotropic axis of juvenile coho salmon to alterations in plane of nutrition with an analysis of the relationships among growth rate and circulating IGF-I and 41kDa IGFBP
| Autor: | Brian R. Beckman, Kathleen A. Cooper, Munetaka Shimizu, Brad A. Gadberry |
|---|---|
| Rok vydání: | 2004 |
| Předmět: |
Male
medicine.medical_specialty Biometry Time Factors Somatotropic cell medicine.medical_treatment Biology Growth hormone Body weight Sex Factors Endocrinology Internal medicine medicine Animals Juvenile Growth rate Insulin-Like Growth Factor I Growth factor Plasma levels Oncorhynchus kisutch In plane Insulin-Like Growth Factor Binding Protein 3 Growth Hormone Regression Analysis Animal Nutritional Physiological Phenomena Female Animal Science and Zoology |
| Zdroj: | General and Comparative Endocrinology. 135:334-344 |
| ISSN: | 0016-6480 |
| DOI: | 10.1016/j.ygcen.2003.10.013 |
| Popis: | The effect of different feeding levels on plasma levels of insulin-like growth factor-I (IGF-I), 41 kDa insulin-like growth factor binding protein (41 kDa IGFBP), and growth hormone (GH) were assessed in post-smolt coho salmon. Fish were fed at either stable (1 and 2% body weight/day) or varying (1-0.5-1%, 2-0.5-2% body weight/day) feeding rates and plasma was sampled from 10 fish/treatment at 2-3 week intervals over five dates from June to September, resulting in a total of 200 samples. Fish fed at higher rates grew faster and had higher plasma IGF-I and 41 kDa IGFBP levels. Plasma GH levels were variable but generally showed an inverse relationship to feeding rate. Both plasma IGF-I and 41 kDa IGFBP increased seasonally, average IGF-I levels doubled from June to September, regardless of feeding rate. On any one date both IGF-I and 41 kDa IGFBP were highly related to growth rate with regression coefficients ranging from 0.36 to 0.68 (IGF-I) and from 0.33 to 0.70 (41 kDa IGFBP). No relationship was found between IGF-I:41 kDa IGFBP ratio and individual growth rate. Overall, both feeding rate and date were important in explaining variation in IGF-I and 41 kDa IGFBP levels. |
| Databáze: | OpenAIRE |
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