| Project/Area Number |
01570498
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
Circulatory organs internal medicine
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| Research Institution | University of the Ryukyus |
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Principal Investigator |
TAKISHITA Shuichi Univ. of the Ryukyus Sch. of Medicine Associate Professor, 医学部, 助教授 (90108712)
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| Co-Investigator(Kenkyū-buntansha) |
KIMURA Yorio Univ. of the Ryukyus Sch. of Medicine Assistant Professor, 医学部, 助手 (50177937)
KAWAZOE Nobuyuki Univ. of the Ryukyus Sch. of Medicine Assistant Professor, 医学部, 助手 (10177694)
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| Project Period (FY) |
1989 – 1990
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| Project Status |
Completed (Fiscal Year 1990)
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| Budget Amount *help |
¥2,100,000 (Direct Cost: ¥2,100,000)
Fiscal Year 1990: ¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 1989: ¥1,400,000 (Direct Cost: ¥1,400,000)
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| Keywords | Renal blood flow / Renal nerve activity / Blood pressure / Baroreceptor reflex / Conscious / Stress / Hypertension / エア-ストレス / 無麻酔 / 圧反射 / 降圧薬 |
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| Research Abstract |
Several studies have established the role of the sympathetic nervous system for renal hemodynamics in anesthetized animals. The aim of the present study is to investigate influences of the baroreceptor reflex and of air stress on renal blood flow by simultaneous recording of sympathetic nerve activity (RSNA) and blood flow (RBF) to the kidney in conscious rabbits which equipped with a pulsed Doppler flow probe around the left renal artery and an electrode placed under the left renal nerve.
1. In resting and motionless state, there were no significant correlations among levels of or changes in mean blood pressure (MBP). RSNA and RBF.
2. RBF was decreased during nitroprusside-induced fall of MBP. showing a significant negative correlation with percentage changes in RSNA. Nitroprusside, however, could not reduce MBP below 55 mmHg even at a dose of 10 Mg/kg/min.
3. In rabbits with pretreatment with denervation of bilateral aortic depressor and carotid sinus nerves, fluctuations of MBP, RSNA and RBF were larger than in normal animals. There was tendency to dependence of RBF on levels of MBP.
4. Air stress evoked elevations of MBP and RSNA each of which significantly correlated with a simultaneous decrease in RBF.
These results suggest that at the cost of slight suppression of RBF through the enhanced RSNA in face to a fall in blood pressure the maintaining proper level of blood pressure by the baroreceptor reflex has an important role in preventing RBF from an extreme reduction. Elevations of blood pressure and RSNA associated with a decrease in RBF in response to stress might indicate a significant contribution of stress to initiation and maintenace of hypertension.
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