Reduced serum insulin-like growth factor (IGF) I is associated with reduced liver IGF-I mRNA and liver growth hormone receptor mRNA in food-deprived cattle1

Nutritional deprivation decreases blood insulin-like growth factor I (IGF-I) concentrations in a variety of species. In this study, we explored the underlying mechanism by determining the effects of food deprivation on the levels of total IGF-I mRNA and total growth hormone receptor (GHR) mRNA, as w...

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Bibliographic Details
Published inThe Journal of nutrition Vol. 133; no. 8; p. 2555
Main Authors Wang, Ying, Eleswarapu, Satyanarayana, Beal, William E, Swecker, William S
Format Journal Article
LanguageEnglish
Published Bethesda American Institute of Nutrition 01.08.2003
Subjects
Cattle
Food
Insulin
Liver
Ribonucleic acid
RNA
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Summary:Nutritional deprivation decreases blood insulin-like growth factor I (IGF-I) concentrations in a variety of species. In this study, we explored the underlying mechanism by determining the effects of food deprivation on the levels of total IGF-I mRNA and total growth hormone receptor (GHR) mRNA, as well as the levels of individual IGF-I mRNA variants and GHR mRNA variants in the liver of steers. Food deprivation for nearly 3 d decreased the levels of serum IGF-I by 63% (P < 0.01), and this decrease was associated with a 75% decrease (P < 0.01) in total IGF-I mRNA in the liver. The food deprivation-induced decrease in liver total IGF-I mRNA was associated with an equivalent decrease in the levels of both class 1 and class 2 IGF-I mRNA. In addition to IGF-I mRNA, food deprivation also decreased the levels of total GHR mRNA in the liver (P < 0.05), and this decrease was associated with a decrease in the liver expression of GHR mRNA variants 1C3 (P < 0.05) and 1A (P = 0.08). Food deprivation did not affect the levels of two other major GHR mRNA variants, 1B and 1C2, in the liver. These results demonstrate that the food deprivation-induced decrease in circulating IGF-I in steers is associated with a coordinate decrease in the expression of different IGF-I mRNA variants and a specific decrease in the expression of GHR mRNA variants 1C3 and 1A in the liver. J. Nutr. 133: 2555-2560, 2003. [PUBLICATION ABSTRACT] KEY WORDS: [middot] cattle [middot] liver [middot] mRNA [middot] insulin-like growth factor I [middot] growth hormone receptor
ISSN:0022-3166
1541-6100