1990 Fiscal Year Final Research Report Summary
Cryopreservation of Hamster Pancreatic Islets Using a Rapid Cooling Rate
| Project/Area Number |
63570626
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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 |
Digestive surgery
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| Research Institution | 福井医科大学 |
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Principal Investigator |
KOJIMA Yasuhiko Faculty of Medicine , Fukui Medical School , Assistant Professor, 医学部, 講師 (00135071)
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| Co-Investigator(Kenkyū-buntansha) |
NOTE Masayuki Faculty of Medicine , Fukui Medical School , Assistant, 医学部, 助手 (60189412)
NAKAGAWARA Gizo Faculty of Medicine , Fukui Medical School , Professor, 医学部, 教授 (10019549)
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| Project Period (FY) |
1988 – 1990
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| Keywords | Pancreatic Islet / Cryopreservation / Labelling Index / Xenogeneic Transplantation |
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| Research Abstract |
To clarify the possibility of developing a rapid cooling rate for islet cryopreservation, we used a cooling rate of 25^ﾟC/min for hamster pancreatic islet cryopreservation using 15% dimethylsulfoxide as a cryoprotectant. After preservation, these islets were examined their morphology and function ssaying the insulin release after glucose stimulation and the contents of the insulin and DNA in 10 islets. In addition, islet cell replicatory activity was investigated by an autoーradiographic technique. The effects of transplantation of the islets upon isogeneic and xenogeneic transplantation were also examined.
Freezing using a rapid cooling rate of 25^ﾟC/min was found to be as effective as a slow cooling rate of 1^ﾟC/min for hamster islet cryopreservation. Morphologically the cryopreserved islets appeared to be similar to the non-frozen cultured islets. The glucose-stimulated insulin releaseand cell replicatory activities "in vitro" also remained unchanged, whereas the number of cells per islet decreased slightly after cryopreservation. The grafting of cryopreserved islets normalized streptozotocin induced hyperglycemia following isogeneic transplantation. On the other hand, no prolongation of graftsurvivals in the case of the xenogeneic transplantation of hamster islets to rats was observed. The isogeneically transplanted islets exhibited the same cell replicatory activities "in vivo", which was even higher compared to that of normal hamster pancreatic islets in situ.
In conclusion, the present findings indicate that hamster pancreatic islets can be successfully cryopreserved using a raped cooling rate, however, it does not appear that this treatment reduces islet vulnerability to xenogeneic graft rejection.
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