Effect of hypophysectomy on insulin-like growth factor (IGF)-1 binding activity of serum in chickens.
1. Hypophysectomy elevated IGF-1 binding activity of serum concurrently with decreases in circulating concentrations of IGF-1 and growth hormone (GH). 2. When sera pooled from each experimental group were chromatographed on a Sephadex G-200 column, IGF-1 binding activity was mainly found in 150 and 30 kilodalton (kDa) proteins. 3. Most of the serum IGF-1 were distributed among 150 kDa protein fractions. 4. Hypophysectomy elevated IGF-1 binding activity of these proteins, especially that of 30 kDa protein. 5. The binding of [125I]IGF-1 to the 30 kDa protein was inhibited by unlabelled IGF-1 but not by insulin, and saturated with a small amount of the ligand compared to the 150 kDa protein. 6. The IGF-1 binding activity of 30 kDa protein was dependent on GH status of chickens.
Morishita
D
D
Faculty of Bioresources, Mie University, Tsu, Japan.
Wakita
M
M
Hoshino
S
S
D000818:Animals; D002352:Carrier Proteins / Q000097:blood*; D002645:Chickens / Q000097:blood*; D013006:Growth Hormone / Q000097:blood; D007016:Hypophysectomy; D018970:Insulin-Like Growth Factor Binding Protein 1; D007334:Insulin-Like Growth Factor I / Q000378:metabolism*; D008297:Male; D008970:Molecular Weight; D010902:Pituitary Gland / Q000502:physiology*
D002352:Carrier Proteins; D018970:Insulin-Like Growth Factor Binding Protein 1; D007334:Insulin-Like Growth Factor I; D013006:Growth Hormone