Project/Area Number |
10218202
|
Research Category |
Grant-in-Aid for Scientific Research on Priority Areas
|
Allocation Type | Single-year Grants |
Review Section |
Biological Sciences
|
Research Institution | University of Tokyo |
Principal Investigator |
HIRATA Yasunobu Univ. of Tokyo, Medicine, Associate Prof., 医学部附属病院, 講師 (70167609)
|
Co-Investigator(Kenkyū-buntansha) |
SATA Masataka Univ. of Tokyo, Medicine, Lecturer, 医学部附属病院, 助手 (80345214)
SUZUKI Etsu Univ. of Tokyo, Medicine, Lecturer, 医学部附属病院, 助手 (40313134)
|
Project Period (FY) |
1998 – 2002
|
Project Status |
Completed (Fiscal Year 2002)
|
Budget Amount *help |
¥65,700,000 (Direct Cost: ¥65,700,000)
Fiscal Year 2002: ¥12,600,000 (Direct Cost: ¥12,600,000)
Fiscal Year 2001: ¥12,600,000 (Direct Cost: ¥12,600,000)
Fiscal Year 2000: ¥13,500,000 (Direct Cost: ¥13,500,000)
Fiscal Year 1999: ¥13,500,000 (Direct Cost: ¥13,500,000)
Fiscal Year 1998: ¥13,500,000 (Direct Cost: ¥13,500,000)
|
Keywords | adrenomedullin / nitric oxide / endothelium / PI3-K / Akt / vasodilation / knockout mice / ischemia / アドレノメデュリン / cGMP / cAMP / アポトーシス / 低酸素 / 遺伝子 / 尿細管 / 血管平滑筋細胞 |
Research Abstract |
Adrenomedullin is a vasodilatory peptide and major source of circulating adrenomedullin is the vascular wall. The vascular action of adrenomedullin was at first considered to solely due elevated cAMP production, I. e., endothelium-independent vasodilation. However, we found that endothelial denudation substantially reduced the vasodilatory action of adrenomedullin in rodent aortic rings. Furthermore, this adrenomedullin-induced endothelium-dependent vasorelaxation is exerted mostly through activation of the phosphatydil inositol 3-kinase (PI3-K)/Akt pathway. It has been well established that this pathway is involved in various important actions such as anti-apoptosis and tissue protection as well as activation of endothelial nitric oxide synthase (eNOS). Furthermore, we have reported that expression of the adrenomedullin gene is upregulated by hypoxia. Adrenomedullin abrogates ischemia/reperfusion renal injury. Studies using adrenomedullin gene knockout mice revealed that adrenomedullin plays an important role in vascular formation in embryos. Adrenomedullin transgenic mice were resistant to ischemia/reperfusion renal injury and adrenomedullin knockout mice vice versa. These findings suggest that endogenous adrenomedullin may play an important role as a tissue survival factor.
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