Influence of donor age on bovine pancreatic islet isolation

Background. Pancreatic islets from pigs are largely used for experimental s tudies. However, pancreas harvesting requires modification of conventional slaughtering to reduce ischemia time. It has been shown that bovine pancrea tic islets can be more easily obtained and they show satisfactory in vitro and in vivo function. To improve the isolation procedure we compared the ef fect of bovine donor age on islet isolation. Methods. Islets were isolated by collagenase digestion and sequential sievi ng from calves (6 months of age) and from adult bovine (> 16 months of age) . After isolation the number of islet equivalents was calculated and histol ogical and immunohistochemical studies performed, The purity and viability of islet for each preparation was also estimated. In vitro function of isle ts was evaluated by static insulin secretion assay, and alginate encapsulat ed islets were transplanted in streptozotocin-induced diabetic rats for in vivo functional evaluation. Results. A significantly higher number of islets were obtained from calf pa ncreas, compared with adult bovine pancreas. Hystological examination showe d intact morphologic features of islets. The purity of islet preparations w as higher from calf pancreas than from adult pancreas. Cell viability, and insulin production in presence of high glucose concentration, were not affe cted by donor age. All animals receiving microencapsulated islets from calv es showed normoglycemia for prolonged periods (17-40 days). Conclusions. These results indicate that pancreatic islet isolation is more efficient from juvenile bovine than from adult. Calf pancreas is a good an d convenient source of tissue for massive islet isolation for experimental studies.