To set up an economic and effective method for islet isolation from rat, and thereby prove a laboratory protocol of animal model for cl inical islet transplantation. Methods Twenty-five adult male SD rats weighing 230-380 g were used as organ donor. In each of 5 repeated experiments, pancreatic islets of 5 animals were isolated by intraductal infusion of compound sodium chloride injection (CSCI), and subsequently, digested with low concentration (0.5 mg/mL)of collagenase V solution. Islet purification was performed by using a discontinuous density gradient centrifugation thatwas prepared with 27.0%, 23.0%, 20.5% and 11.0% of Ficoll 400. Islet yield and purity were determined by dithizon (DTZ)stain, and propidium iodide (PI)/fluorescein diacetate (FDA) double stain was used to check viabil ity of islets. The endocrine secretory function was assessed by insul in secretion in either low (2.8 mmol/L) or high (25.0 mmol/L) glucose incubation after 3 days of culture in RPMI1640 media. Results Average islet digestion time of 5 experiments was (13.8 ± 1.6) min. Before purification, average isolated number was (5 626 ± 422) islets, and the number was significantly reduced to (2 914 ± 485) islets after purification (P lt; 0.01). The average recovery rate was 51.6% ± 6.0%, and the average yield was (583 ± 97) islets/pancreas. The average purity and viabil ity of islets were 90.2% ± 3.4% and 81.6% ± 7.0%, respectively. After 3 days of culture, insul in secretion of the islets was (116.1 ± 17.4) EU/L in high glucose incubation, which was significantly higher than that of low glucose environment [(39.7 ± 7.5) EU/L, P lt; 0.01)]. The average insul in stimulation index was 3.0 ± 0.4. Conclusion The islet isolation with the CSCI solution and digestion with low concentration of collagenase V decrease experimental cost and also have a beneficial effect on islet recovery and their function.
