| Project/Area Number |
15590787
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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 |
Circulatory organs internal medicine
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| Research Institution | National Cardiovascular Center Research Institute |
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Principal Investigator |
AKIYAMA Tsuyoshi National Cardiovascular Center Research Institute, Dept.of Cardiac Physiology, Section Chief, 心臓生理部, 室長 (70202554)
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| Co-Investigator(Kenkyū-buntansha) |
YAMAZAKI Toji National Cardiovascular Center Research Institute, Dept.of Cardiac Physiology, Section Chief, 心臓生理部, 室長 (20116122)
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| Project Period (FY) |
2003 – 2004
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| Project Status |
Completed (Fiscal Year 2004)
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| Budget Amount *help |
¥2,900,000 (Direct Cost: ¥2,900,000)
Fiscal Year 2004: ¥1,000,000 (Direct Cost: ¥1,000,000)
Fiscal Year 2003: ¥1,900,000 (Direct Cost: ¥1,900,000)
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| Keywords | hypertensive rat / sympathetic nerve endings / microdialysis technique / norepinephrine / dihydroxyphenylglycol / norepinephrine reuptke / 骨格筋交感神経終末 / ノルエピネフリン分泌 / 心臓交感神経終末 / 星状神経節刺激 |
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| Research Abstract |
To elucidate whether sympathetic nerve ending functions are impaired in essential hypertension, we applied dialysis technique to the left ventricular myocardium of anesthetized SHR and WKY rats (20 weeks) and monitored myocardial interstitial norepinephrine(NE) and dihydroxyphenylglycol(DHPG) levels as indexes of NE release and intraneuronal NE metabolism on cardiac sympathetic nerve endings.
There was no difference in heart rate between SHR and WKY, but the mean arterial pressure, the weight of wet heart, plasma NE concentration, and plasma DHPG concentration in SHR were higher than those in WKY.
There was no difference in myocardial interstitial NE levels between SHR and WKY, but high K^+- and tyramine-induced interstitial NE responses in SHR were lower than those in WKY. These results suggest that NE release function on cardiac sympathetic nerve endings is impaired in SHR. There was no difference in myocardial interstitial DHPG levels and desipramine (NE reuptake inhibitor) -induced i
… More
nterstitial NE responses between SHR and WKY. These results suggest that NE reuptake and intraneuronal NE metabolic functions on cardiac sympathetic nerve endings are intact in SHR.
Then, we focused on skeletal muscle sympathetic nerves innervating resistant arteries as causes of high plasma NE and DHPG levels. We applied dialysis technique to the left femoral skeletal muscle of anesthetized SHR and WKY rats (20 weeks) and monitored skeletal muscle interstitial NE and DHPG levels as indexes of NE release and intraneuronal NE metabolism on skeletal muscle sympathetic nerve endings.
Skeletal muscle interstitial NE levels in SHR were higher than those in WKY. High K^+- and tyramine-induced interstitial NE responses in SHR were higher than those in WKY. These results suggest that NE release function on skeletal muscle sympathetic nerve endings is enhanced in SHR and this enhancement contributes to high plasma NE levels. Skeletal muscle interstitial DHPG levels in SHR were higher than WKY, but there was no difference in DHPG/NE ratios and desipramine-induced interstitial NE responses between SHR and WKY. These results suggest that NE reuptake and intraneuronal NE metabolic functions on skeletal muscle sympathetic nerve endings are intact in SHR. Less
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