Factors to consider in the assessment of viability of cryopreserved islets of Langerhans.
With the development of techniques for the isolation and transplantation of pancreatic islets of Langerhans, research has been directed toward low-temperature storage of islets as a means of preservation. For successful islet cryopreservation several factors must be considered. In these studies we have investigated the effects of the cryoprotectant dimethyl sulfoxide (Me2SO) on islet function in the absence of freezing. We have found that Me2SO pretreatment can inhibit subsequent glucose-induced insulin release, but this effect can be minimized by hypothermic exposure to the cryoprotectant using a stepwise addition and dilution protocol for treatment. By studying islet function after freezing and thawing, we have found also that a slow cooling rate (0.3 degrees C/min) results in optimal survival and that islet function can be significantly improved by increasing the duration of post-thaw culture. The results of these studies address only a few of the many questions that need to be answered before clinical application of cryopreserved islet transplantation occurs.
D000818:Animals; D004121:Dimethyl Sulfoxide / Q000494:pharmacology; D005615:Freezing; D007328:Insulin / Q000378:metabolism; D000078790:Insulin Secretion; D007515:Islets of Langerhans / Q000166:cytology* / Q000378:metabolism / Q000502:physiology; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D014021:Tissue Preservation / Q000379:methods*; D014022:Tissue Survival
D007328:Insulin; D004121:Dimethyl Sulfoxide