Establishment of a prolonged pancreas preservation model for islet isolation research in mice

Establishing a prolonged pancreas preservation model in a small animal is important for islet isolation research. Use of a rat pancreas model has been reported, but no published reports have used a mouse pancreas for prolonged cold preservation prior to islet isolation. For the model, a mouse is preferred over a rat because of its small size, well-known immune characterization and variety of gene-modulated models. In the present study, we established a prolonged pancreas preservation model in a mouse for islet isolation research. The collagenase solution was injected successfully after 24 and 48 h cold preservations in University of Wisconsin solution, and islets could be isolated from both groups of preserved pancreata. The islet yields from the control, 24 and 48 h preserved pancreata were 183.9 +/- 13.9, 128.5 +/- 15.5 and 24.6 +/- 12.9 per pancreas, respectively. The propidium iodide-positive area assay was significantly increased in both preserved groups, and insulin secretion levels in response to 20.0 mM glucose and stimulation indices were significantly decreased in the 48 h preserved group. Inflammation-related genes mRNA levels were significantly upregulated in the 24 h preserved group, as previously shown in the human model. Thus, this model might be useful for prehuman islet isolation screening research, reserving research using human pancreata for the most promising approaches.