1992 Fiscal Year Final Research Report Summary
Evaluation of immature myocardial energy metabolism during ischemia and after reperfusion by NMR spectroscopy
Project/Area Number |
03454339
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Research Category |
Grant-in-Aid for General Scientific Research (B)
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Allocation Type | Single-year Grants |
Research Field |
Thoracic surgery
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Research Institution | Kinki University |
Principal Investigator |
KATAYAMA Osamu Kinki University, Cardiovascular Surgery, Assistant Professor, 医学部, 講師 (90177402)
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Co-Investigator(Kenkyū-buntansha) |
INOUE Satoshi Kinki University, Cardiovascular Surgery, Assistant Professor, 医学部, 助手 (80232536)
KITAYAMA Hitoshi Kinki University, Cardiovascular Surgery, Assistant Professor, 医学部, 講師 (50224978)
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Project Period (FY) |
1991 – 1992
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Keywords | Immature Myocardium / Ischemia / Reperfusion / Cardioplegia / NMR Spectroscopy / Rabbit Heart / ATP |
Research Abstract |
Multidose infusion of crystalloid cardioplegia has been reported to be detrimental to immature myocardium by many investigators. We investigated the effect of multidose cold blood cardioplegia (CBC) on immature myocardium in comparison with St. Thomas' cardioplegia (ST). Hearts from neonatal rabbits (6-9 days) were perfused at 37 OC in the Langendorff method before and after ischemia. Myocardial viability was evaluated by NMR spectroscopy and was expressed in % of preischemic value (mean * SE). Myocardial water content was measured by the wet and dry method. Immature hearts (five in each group) received a single 10 ml infusion of each cardioplegic solution or multiple infusions ( at 15-, 30-, or 60-min.intervals ) at 15 OC during 3 hrs of ischemia. After reperfusion for 30 mins., a single dose of ST showed good recovery of ATP (91.7 * 2.6%), but more frequent infusions of ST worsened ATP recovery (63.1 * 5.0% in the 15-min. interval group,p<0.01 vs single-dose group). In contrast CBC at 15-min.intervals produced best recovery of ATP (95.1 * 3.6%), and multidose CBC infusion improved postischemic ATP recovery (75.1 * 3.7% in single-dose group, p<0.05 vs multidose groups). Myocardial water contents in ST groups were significantly higher than in CBC groups, however, they had no relationship with ATP recovery. These observations suggest that multidose cardioplegic infusion is not always detrimental to the immature heart and that the Immature heart may be more sensitive than the adult heart to the combination of cardioplegic solution and infusion method. In conclusion we have to find a suitable infusion method for the cardioplegic solution adopted.
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