Influence of a Current Style of Culture on the Quality of Isolated Pancreatic Islets

Abstract

Objective Comparable outcomes of islet transplantation with short periods of culture may be achieved with various culture media. To clarify the influence of a style of culture on isolated pancreatic islets, islet quality of fresh islets was compared with those cultured in several different fashions including not only for viability but also for inflammatory mediators. Materials and Methods Wistar rat islets were cultured for 48 hours with CMRL including 10% allogeneic serum; CMRL including 0.5% human serum albumin (HSA); and Miami medium including 0.5% HSA. The influence of culture conditions on islet integrity was evaluated by survival rate of islets during culture and visual scoring. The influence of culture conditions on islet function and viability was examined by ADP/ATP tests, insulin/DNA content, and glucose stimulation tests. Results Although the survival rates were similar for all groups, the visual scoring was lower in Miami medium. The stimulation index in glucose challenge tests was higher for fresh islets than the media ( P = .02). Insulin/DNA ratios revealed the same tendency as glucose challenge tests ( P = .0005). ADP/ATP ratio was lower in both the fresh and serum groups than in the others ( P = .38), suggesting that apoptotic islets are relatively fewer in both fresh and serum groups. Most importantly, the expression of tissue factor (TF) on the islets was considerably lower in the fresh group, suggesting that a current style of culture could enhance TF-dependent instant blood-mediated inflammatory reactions after transplantation. Conclusion In conclusion, Isolated islets without prior culture shows characteristics beneficial for transplantation using current modes of culture.