| Project/Area Number |
16500258
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Neurophysiology and muscle physiology
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| Research Institution | Akita University |
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Principal Investigator |
KAWATANI Masahito Akita Univ., School of Medicine, Neurophysiology, Professor, 医学部, 教授 (00177700)
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| Co-Investigator(Kenkyū-buntansha) |
MOMOTA Y. Akita Univ., School of Medicine, Neurophysiology, Assistant Professor, 医学部, 助手 (70295236)
YANASE Y. Akita Univ., School of Medicine, Neurophysiology, Assistant Professor, 医学部, 助手 (10400483)
中村 靖夫 秋田大学, 医学部, 助手 (20322117)
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| Project Period (FY) |
2004 – 2005
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| Project Status |
Completed (Fiscal Year 2005)
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| Budget Amount *help |
¥3,600,000 (Direct Cost: ¥3,600,000)
Fiscal Year 2005: ¥1,200,000 (Direct Cost: ¥1,200,000)
Fiscal Year 2004: ¥2,400,000 (Direct Cost: ¥2,400,000)
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| Keywords | Urothelium / α_<1D> Receptor / EP_1 Receptor / Primary afferent / Unit recording / Primary afferent / Unit recording / α_<1D> Receptor / 求心性線維 / プロスタグランジン / EP1受容体 / α1受容体 / ATP / 膀胱炎 |
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| Research Abstract |
Previous studies revealed that activation of alpha_1 adrenergic receptors in urothelial cells releases neurotransmitters. This study was undertaken to determine if alpha_<1D> adrenergic receptors are expressed in the urothelium of the rat bladder and if inhibition of these receptors affects reflex voiding. Female Wistar rats were used for the experiments. Receptor expression was evaluated by Western blot. The effects of receptor activation were studied using cystometrograms, measurement of ATP concentrations in the bladder lumen and afferent nerve recording. The alpha_<1D> antagonist, naftopidil (0.75-1.66 mg/kg) was administered intravenously into the external jugular vein. Expression of alpha_<1D> adrenergic receptors was detected in urothelial tissue with Westernblot and Immunohistochemistry. The alpha_<1D> receptor antagonist, naftopidil prolonged the intercontraction interval (ICI, 143 % of the control) during continuous infusion cystometrograms in conscious rats, and suppressed the excitatory effect of intravesical infusion of acetic acid (0.1 %) on the ICI (220 %). Naftopidil inhibited bladder afferent nerve activity induced by bladder distension (32.0%) or acetic acid infusion (30.4 %) and reduced the ATP levels in the bladder perfusate during bladder distension (36.6 %). Endogenous catecholamines appear to act on alpha_<1D> receptors in the urothelium to facilitate the mechano-sensitive bladder afferent nerve activity and reflex voiding.
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