Effect of a methmazole induced hypothyroidism on a growth hormone induced insulin-like growth factor I response in normal and sex-linked dwarf domestic fowl

Huybrechts, LM; Michielsen, R; Darras, Veerle; Berghman, LR; Decuypere, E; Kühn, ER

Effect of a methmazole induced hypothyroidism on a growth hormone induced insulin-like growth factor I response in normal and sex-linked dwarf domestic fowl

Author:

Huybrechts, LM

Michielsen, R ; Darras, Veerle ; Berghman, LR ; Decuypere, E ; Kühn, ER

Keywords:

General & Internal Medicine

Abstract:

Both normal and dwarf birds were treated with methimazole (MMI) to investigate the effect of low thyroid hormone levels on the synthesis of insulin-like growth factor-1 (IGF-I). MMI treatment resulted in lower thyroid hormone levels in both normal and dwarf birds and in decreased IGF-I levels in normal birds, but not in dwarf animals. An injection of growth hormone (GH) resulted in increased IGF-I levels 24 and 48 hours after injection and this in both normal and dwarf control and MMI fed birds. This increase in IGF-I level swas lower in dwarf and MMI treated birds. Both the smaller increase in birds with low triiodothyronine (T3) levels (dwarfs and MMI treated) and the decrease in T3levels during IGF-I synthesis may be an indication of the role of T3in controlling IGF-I production.