| Project/Area Number |
17300204
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (B)
|
| Allocation Type | Single-year Grants |
|---|
| Section | 一般 |
|---|
| Research Field |
Sports science
|
|---|
| Research Institution | Teikyo Heisei University (2007)
University of Tsukuba (2005-2006) |
|---|
Principal Investigator |
MESAKI Noboru Teikyo Heisei University, Faculty of Health Care, Professor (30010408)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
MAEDA Seiji University of Taukuba, Graduate School of Comprehensive Human Sciences, Lecturer (30282346)
IEMITSU Motoyuki Nara Sangyo University, Research Center for Higher Education, Lecturer (90375460)
AIZAWA Katsuji University of Tsukuba, Graduate School of Comprehensive Human Sciences, Researcher (80375477)
|
|---|
| Project Period (FY) |
2005 – 2007
|
| Project Status |
Completed (Fiscal Year 2007)
|
| Budget Amount *help |
¥16,340,000 (Direct Cost: ¥15,200,000、Indirect Cost: ¥1,140,000)
Fiscal Year 2007: ¥4,940,000 (Direct Cost: ¥3,800,000、Indirect Cost: ¥1,140,000)
Fiscal Year 2006: ¥4,200,000 (Direct Cost: ¥4,200,000)
Fiscal Year 2005: ¥7,200,000 (Direct Cost: ¥7,200,000)
|
|---|
| Keywords | skeletal muscle / sex hormone / autocrine / exercise / aging / トレーニング / 自己産生 |
|---|
| Research Abstract |
Sex steroid hormones, such as testosterone and estradiol, play important roles in developing both strength and mass of skeletal muscle. Circulating dehydroepiandrosterone (DHEA)is peripherally taken up and converted to testosterone by 3B-hydroxysteroid dehydrogenase (HSD) and 17B-HSD, and testosterone, in turn, is irreversibly converted to estrogens by aromatase cytochrome P450 (P450arom). Although sex steroid hormones have been implicated in skeletal muscle regulation and adaptation, it is unclear whether skeletal muscles have a local steroidogenic enzymatic machinery capable of metabolizing circulating DHEA. First study, we investigate whether the three key steroidogenic enzymes are present in the skeletal muscle, and are capable of generating sex steroid hormones. These findings are novel and important in that they provide the first evidence showing that skeletal muscles are capable of locally synthesizing sex steroid hormones from circulating DHEA or testosterone. Second study, we examine sex differences in the levels of testosterone, estradiol, and steroidogenesis-related enzymes, such as 3B-HSD, 17B-HSD and P450arom, in the skeletal muscle at rest and after exercise. We studied the gastrocnemius muscles of resting rats(10 weeks old)and exercised rats(10 weeks old, treadmill running, 30 m/min, 30 min). A single bout of exercise can influence the steroidogenic system in skeletal muscle and these alterations differ between sexes. The acute exercise-induced alteration of steroidogenic enzymes may enhance the local steroidogenesis in the skeletal muscle in both sexes.
|
