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Responses of insulin-like growth factor (IGF)-I and two IGF-binding protein-1 subtypes to fasting and re-feeding, and their relationships with individual growth rates in yearling masu salmon (Oncorhynchus masou).
- Source :
-
Comparative Biochemistry & Physiology Part A: Molecular & Integrative Physiology . Jun2013, Vol. 165 Issue 2, p191-198. 8p. - Publication Year :
- 2013
-
Abstract
- Abstract: Two subtypes of insulin-like growth factor binding protein (IGFBP)-1 are present in salmon blood and they are both up-regulated under catabolic conditions such as stress. The present study examined effects of fasting and re-feeding on IGFBP-1a (28-kDa form) and IGFBP-1b (22-kDa form) both at mRNA and protein levels along with IGF-I and RNA/DNA ratio in yearling masu salmon. Fish were individually tagged and assigned to one of three treatments: Fed, Fasted or Re-fed. Circulating IGF-I levels significantly decreased after fasting for 5weeks and were positively correlated with individual growth rates. Liver igf-1 mRNA levels were not affected by the treatment. Muscle RNA/DNA ratio did not respond to fasting nor showed correlations with growth rates. Circulating IGFBP-1a and IGFBP-1b increased during fasting and decreased after re-feeding. Both serum levels were inversely correlated with growth rates, while IGFBP-1b had consistent negative relationships with growth rates. Fasting/re-feeding also affected their mRNA levels in the liver. These results suggest that circulating IGF-I and IGFBP-1b could serve as positive and negative indices of growth, respectively, in masu salmon. Different sensitivities of IGBP-1a and IGFBP-1b may be useful to assess a broad range of catabolic conditions when they are combined. [Copyright &y& Elsevier]
Details
- Language :
- English
- ISSN :
- 10956433
- Volume :
- 165
- Issue :
- 2
- Database :
- Academic Search Index
- Journal :
- Comparative Biochemistry & Physiology Part A: Molecular & Integrative Physiology
- Publication Type :
- Academic Journal
- Accession number :
- 89076692
- Full Text :
- https://doi.org/10.1016/j.cbpa.2013.02.029