Long-term preservation of rat pancreatic islets under physiological conditions

In this study, we found that islet cells treated with polyphenol could be preserved for over 2 months under physiological conditions retaining their original function and maintaining their spherical shapes without any insulin secretion. When islets were treated at higher concentration than 250 microg ml(-1), these islets could retain their compact spherical shape over 65 days whereas non-treated islets were scattered ease to break within 2 weeks. The secretional capacity from treated islets in the initial stage is also lower than untreated islets. However, in the case of untreated islets, insulin release rapidly lowered with the progress in the culture time and secretion completely disappeared after 9 days. On the contrary, islets treated with polyphenol (250 microg ml(-1)) in RPMI culture medium showed significant enhancement of insulin secretion on 40th day. The secretional capacity of islets was greatly dependent on the treating concentration. Polyphenol treatment may be a useful method for preservation of mammalian islet cells. By changing the concentration of polyphenol, it is possible to control the preservation duration and insulin secretion of islets.