1991 Fiscal Year Final Research Report Summary
Basic Research of Neural Control of Coronary Circulation.
| Project/Area Number |
01570053
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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 |
General physiology
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| Research Institution | National Cardiovascular Center Research Instutite |
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Principal Investigator |
NINOMIYA Ishio National Cardiovascular Center Research Institute Head, 心臓生理部, 部長 (80033976)
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| Co-Investigator(Kenkyū-buntansha) |
NISHIURA Naoki National Cardiovascular Center Research Institute, 心臓生理部, 室員 (70132933)
AKIYAMA Tsuyoshi National Cardiovascular Center Research Institute, 心臓生理部, 室員 (70202554)
SHIRAI Mikiyasu National Cardiovascular Center Research Institute, 心臓生理部, 室長 (70162758)
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| Project Period (FY) |
1989 – 1991
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| Keywords | Coronary Circulation / Soft X ray TV system / Coronary diameter / Neural control / Pericoronary nerve activity / Myocardial interstitial norepinephrine |
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| Research Abstract |
In this project, three major subjects were studied in anesthetized and awake animals.
1)Developement of New soft X ray TV system for measuring internal diameter of coronary artery. The new soft X ray TV system have high space (17 um) and time (1-3ms) resolution. Using this system pulmonary vessels diameter responses to various stimali were studied (ref. # 4, 6). Application coronary artery is preparing.
2)Recording of pericoronary nerve activity, cardiac sympathetic nerve activity and other sympathetic nerve activity. We measured pericoronary nerve activity from the anterior descending coronary artery in anesthetized dog (ref#9). The pericornary nerve activity consist of cardiac related rhythmic synchronized discharge. The activity was inhibited by baroceptor input. In cats, the pericoronary nerve activity was diffucult to measure and therefore cardiac sympathetic nerve activity was measured. We found 8-12 cycle/s fundamental rhythm of cardiac sympathetic nerve activity (ref. #1, #3). We
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conducted a new concept concerning mechanism of cardiac-related synchronized discharge (ref. #3). Major sources of cardiac sympathetic nerve activity was thoracic 3 and 2 preganglionic neurons (ref. #7). Our result suggest that number of parallel arranged coronary artery was controlled by number of pre and postganglionic fibers activated in parallel.
3)Development of in vivo monitoring system of myocardial interstitial norepinephrine. To estimate local sympathetic nerve activity to the heart in vitro, we applied a, dialysis technique to the heart and attempted to monitor norepinephrine levels in local myocardial interstitial fluid (ref. #50. New type of diolysis probe consisted of an 18xO. 31 mm dialysis fiber with a 50, 000 mol wt cut off. When the probe was perfused at 5ul/min in vitro, the average recovery rate of norepinephrine was 31.3%. At steady state dislysate norepinephrine concentration was 41 pg/ml and was increased to 82 pg/ml by stellate ganglion stimulation (4 Hz). Using this system, regional myocardial interstitial norepinephrine was measured during coronary occlusion (ref. #8). Interstitial norepinephrine increased in proportion to a decrease in regional myocardial blood flow. Less
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