| Project/Area Number |
02454532
|
|---|
| Research Category |
Grant-in-Aid for General Scientific Research (B)
|
| Allocation Type | Single-year Grants |
|---|
| Research Field |
体育学
|
|---|
| Research Institution | Yamaguchi University |
|---|
Principal Investigator |
MINAGAWA Takashi (1991) Yamaguchi Univ. Liberal Arts, Professor, 教養部, 教授 (50035143)
河合 洋祐 (1990) 山口大学, 教養部, 教授 (00035148)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
MIYATA Hirofumi Yamaguchi Univ. Liberal Arts, Assistant Prof., 教養部, 講師 (90190793)
SUGIURA Takao Yamaguchi Univ. Liberal Arts, Associate Prof., 教養部, 助教授 (80136150)
KAWAI Yosuke Yamaguchi Univ. Liberal Arts, Professor, 教養部, 教授 (00035148)
皆川 孝志 山口大学, 教養部, 教授 (50035143)
|
|---|
| Project Period (FY) |
1990 – 1991
|
| Project Status |
Completed (Fiscal Year 1991)
|
| Budget Amount *help |
¥4,700,000 (Direct Cost: ¥4,700,000)
Fiscal Year 1991: ¥1,200,000 (Direct Cost: ¥1,200,000)
Fiscal Year 1990: ¥3,500,000 (Direct Cost: ¥3,500,000)
|
|---|
| Keywords | muscle activity / masseter muscle / mastication / motoneuron / Soma diameter / oxidative enzyme activity / muscle fiber type / 筋線維 |
|---|
| Research Abstract |
It has recently been pointed out that the decrease in mastication activity by the continuous intake of an easily chewable diet and aging. In this study, in order to clear the effect of the soft diet and aging on the masticatory motor unit, we investigated the morphologic and metabolic properties of the superficial masseter muscle and is motoneuron in the rat. Thirty two rats were divided into four groups ; 8 rats fed hard diet until 4 months after birth (Hard, Young), 8 rats fed soft diet until 4 months (Soft, Young), 8 rats fed hard diet until 22 months (Hard, Old) and 8 rats fed soft diet until 22 months (Soft, Old). Two-way analysis of variance was used to evaluate the significance of differences between the hard and soft, or the Young and old. There were significant decrease in the muscle weight/body weight in soft than hard, in old than young. There were tendency to decrease in oxidative and glycolytic enzyme activity of the muscle in soft than hard, and a significant decrease in glycolytic enzyme activity in old than young. While, in motoneurons innervating the muscle, there was no significant difference in soma diameter between hard and soft, while the significant difference between young and old was demonstrated. There were no significant difference in oxidative enzyme activity of the motoneuron between soft and hard, and a significant decrease was demonstrated in old than young. The reduction in motor unit activity caused by the soft diet is considered to influence on the morphologic and metabolic properties in the superficial masseter muscle but not in its motoneuron. The reduction in the oxidative enzyme activity of motoneurons innervating the aging muscle may be related not only to the oxidative enzyme activity but also to the glycolytic enzyme activity of the muscle.
|
