Insulin administration suppresses an increase in insulin-like growth factor binding protein-2 gene expression stimulated by fasting in the chicken.
1. We examined the changes in plasma IGF-I concentration and tissue IGFBP-2 gene expression of young fasted chickens refed a commercial diet or administered bovine insulin intravenously. 2. Plasma IGF-I concentration was decreased by fasting for 2 d. Although plasma IGF-I concentration was increased by refeeding, it didn't recover to the level of chickens fed a commercial diet ad libitum. 3. Insulin administration lowered plasma IGF-I concentration compared to other groups. 4. Hepatic IGFBP-2 mRNA was increased by fasting for 2 d and decreased by refeeding for 6 h. Insulin administration also decreased hepatic IGFBP-2 gene expression stimulated by fasting to the level of refed chickens. 5. IGFBP-2 mRNA in the gizzard was increased by fasting for 2 d and tended to decrease after refeeding for 6 h. Insulin administration decreased gizzard IGFBP-2 gene expression to less than that in refed chickens. 6. There was no between-treatment difference in IGFBP-2 mRNA in the brain and kidney. 7. These results suggest that the changes in IGFBP-2 gene expression in the liver and gizzard by fasting and refeeding might be partly regulated by the alteration in plasma insulin concentration.
Nagao
K
K
Laboratory of Animal Nutrition, Nagoya University, Japan. i011010d@mbox.media.nagoya-u.ac.jp
Aman Yaman
M
M
Murai
A
A
Sasaki
T
T
Saito
N
N
Okumura
J
J
Kita
K
K
D000818:Animals; D001921:Brain / Q000378:metabolism; D002645:Chickens / Q000378:metabolism*; D005215:Fasting / Q000502:physiology; D018507:Gene Expression Regulation, Developmental; D005895:Gizzard, Avian / Q000378:metabolism; D007328:Insulin / Q000008:administration & dosage* / Q000494:pharmacology; D018971:Insulin-Like Growth Factor Binding Protein 2 / Q000096:biosynthesis / Q000235:genetics*; D007334:Insulin-Like Growth Factor I / Q000096:biosynthesis / Q000235:genetics*; D007668:Kidney / Q000378:metabolism; D008099:Liver / Q000378:metabolism; D008297:Male; D012333:RNA, Messenger / Q000378:metabolism
D007328:Insulin; D018971:Insulin-Like Growth Factor Binding Protein 2; D012333:RNA, Messenger; D007334:Insulin-Like Growth Factor I