1996 Fiscal Year Final Research Report Summary
The reserch of the characteristics of immature heart aiming improvement of cardio-protective method in neonatal open heart surgery.
| Project/Area Number |
07457423
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
小児外科
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| Research Institution | Kyushu University |
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Principal Investigator |
TOSHIMA Yoshiro Kyushu University Medicine Accistant Professor, 医学部, 助手 (10197890)
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| Co-Investigator(Kenkyū-buntansha) |
YASUI Hisataka Kyushu University Medicine Professor, 医学部, 教授 (20089923)
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| Project Period (FY) |
1995 – 1996
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| Keywords | immature heart / cardioprotection / coronary autoregulation / repertusion injury |
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| Research Abstract |
The research was carried out as experiments using rabbits (adults ; age 20-30 weeks, neonates : age 4-5 days)
1.We investigated the coronary autoregulation, one of the physiological function of heart, in neonatal (age of 4-5 days) rabbits and compaired with adults (age of 20-28 weeks).
(Methods) Isolated rabbit hearts were perfused with blood in Langendorff perfusion method using blood cross-circulation system. The coronary perfusion pressure was changed in steps of 10mmHg and coronary blood flow was measured at each pressure. Autoregulatory capacity was quantified by autoregulation index (ArI) at each pressure.
(Result) The neonatal hearts didn't show autoregulation of coronary blood flow at any range of perfusion pressure, while the adult hearts exhibited coronary autoregulation in the pressure range between 30mmHg and 90mmHg.
(Conclusion) Neonatal heart is immatuer in coronatu autoregulation.
2.We investigated the effect of depolarize cardiopegia to the left ventricular (LV) function and coronaty reserve after ischemia-reperfusion in blood perfused isolated neonatal rabbit heart.
(Methods) Isolated rabbit hearts were perfused with blood in Langendorff perfusion method using blood cross-circulation system. LV functional recovery and change of coronary reserve for acethyl choline were measured after global ischemis (37ﾟC,25minutes). Animals were devided into twe groups (each n=4). CP (+) group received depolarize cardioplegic solution when the begining of global ischemia, CP (-) group didn't received depolarize cardioplegic solution.
(Results) Better LV functional recoveryand preservation of coronary reserve were showed in CP (+) group, however not significant.
(Discussion) Depolarize cardioplegic solution was not effective enough in preservation of LV function nor coronary reserve in neonates.
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