表題番号：2014B-378
日付：2015/04/14
研究課題亜鉛欠乏による骨格筋の成長抑制における糖鎖遺伝子の機能的役割
| 研究者所属（当時） | 資格 | 氏名 | |
|---|---|---|---|
| （代表者） | 人間科学学術院 人間科学部 | 教授 | 今泉 和彦 |
| （連携研究者） | 杏林大学医学部 | 助教 | 白土 健 |
- 研究成果概要
- Zinc is one of the essential trace elements for all organisms, and is second in abundance to iron in the body. It is generally accepted that zinc is a cofactor for more than 300 enzymes and about 60% of zinc is contained in skeletal muscle development and its adaptive responses are not fully elucidated. In the present study, we studied the effects of zinc-deficiency on the expression of insulin-like growth factor-1 (IGF-1) receptor (IGF-1R) indifferent types of skeletal muscles in weaned rats. Male Sprague-Dawley rats were fed with a zinc-deficient diet (0.6mg zinc/kg diet) or control diet (35.2 mg/kg diet) for 4 weeks. After the experiment for 2 and 4 weeks, the slow-twitch soleus (SOL) and fast-twitch extensor digitorum longus (EDL) muscles were isolated. Zinc-deficiency for 4 weeks caused a significant reduction in the relative weight of EDL muscles to the body weight. However, that of SOL muscles was not changed by zinc-deficiency. IGF1-R mRNA expression in EDL muscles significantly increased by 1.26- and 1.28-fold in 2 and 4 weeks after the onset of zinc-deficiency, respectively, whereas significant changes were not observed in SOL muscles. By contrast, IGF-1R protein expression in SOL muscles significantly increased by 2.07-fold in 4 weeks after the onset of zinc-deficiency, although significant changes were not observed in EDL muscles. These results suggest that the increased expression og IGF1-R protein in SOL muscles in response to zinc-deficiency play an important role in the attenuation of delayed development of SOL muscles due to reduced plasma levels of IGF-1.