| Budget Amount *help |
¥2,200,000 (Direct Cost: ¥2,200,000)
Fiscal Year 1996: ¥200,000 (Direct Cost: ¥200,000)
Fiscal Year 1995: ¥2,000,000 (Direct Cost: ¥2,000,000)
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| Research Abstract |
Dimethylsulfoxide (DMSO), a cryoprotectant, has the disadvantage of cardiac toxicity. In this research, trehalose (TH) was used as a cryoprotectant for the cryopreservation of cardiac myocytes in order to reduce the toxicity of DMSO,and the cytoprotective effects of TH on the cryopreservation of cardiac myocytes were evaluated. Cryo-preservation of cultured rat cardiac myocytes was performed. The beating rate of myocytes was significantly decreased when the concentration of DMSO was reduced from 10%to5% (39.6% vs 0% ; p<0.01), while it was significantly increased when 0.2M TH was added to 5% DMSO (13.0% ; p<0.05). The release of CPK was the almost same level among the group of 10% DMSO, 10% DMSO with 0.2M TH,5% DMSO, and 5% DMSO with 0.2M TH.In this research, we demonstrated that myocyte beating rate after the cryopreservation could be maintained even with a lower concentration of DMSO in combination with TH,possibly due to the less toxic effect to myocytes. TH might supress the release of CPK by maintaining the stability of the plasma membrane of cardiac myocytes, ggesting that it might be beneficial to the cryopreservation of cardiac myocytes. Next objective of this research is to evaluate the cytoprotective effect of TH on cultured cardiac myocytes of rats preserved under nonfreezing supercooling (-4ﾟC).
Results and conclusion ; With a short preservation time (4 hours), the beating recovery ratio was higher in +4ﾟC group than that in -4ﾟC group. Following long-term (16,24 hours) preservation at -4ﾟC,the beating recovery ratio remained high when TH was used. The release of CPK with TH was lower in -4ﾟC preservation group than that in +4ﾟC group. In this study TH protected rat cultured myocytes from cold injury under supercooling (-4ﾟC) up to 24 hours, suggesting that it might be beneficial to the long term cardiac preservation.
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