Comparison of New Preservation Solutions, HN-1 and University of Wisconsin Solution, in Pancreas Preservation for Porcine Islet Isolation

Abstract

For pancreatic islet transplantation, maintaining organ viability after pancreas procurement is critical and a major determinant for better graft function and survival. University of Wisconsin (UW) solution is currently the gold standard for abdominal organ preservation and the pancreas in particular. However, in the use of UW preservation solution for islet transplantation, there are disadvantages to be overcome, such as the inhibition of collagenase activity during pancreatic digestion. In this study, we compared UW solution with HN-1 solution in pancreas preservation for islet isolation. Islet yield was significantly greater in the HN-1 group than the UW group both before and after purification. In the in vitro assay, the adenosine triphosphate content in cultured islets was significantly higher in the HN-1 group than in the UW group. Furthermore, in streptozotocin-induced diabetic nude mice, the islet graft function of the HN-1 group was superior to that of the UW group. We concluded that the use of HN-1 solution is a promising approach for optimal pancreas preservation in islet transplantation.

Keywords: HN-1 solution; Islet isolation; Islet transplantation; Preservation; University of Wisconsin (UW) solution.

Figure 1

Islet yield before purification and after purification. The HN-1 solution (Center for Promotion of Science Education) group (n = 5) had significantly better islet yield both before (A, total islet yield; B, islet yield/g) and after purification (C, total islet yield; D, islet yield/g) than the University of Wisconsin solution (UW) group (n = 5; p < 0.05). Data are expressed as the mean ± SE.

Figure 2

ATP content of porcine islets. The adenosine triphosphate (ATP) concentration of the cell lysate after islet purification was measured using an ATP assay system. ATP was normalized to islet equivalents (pmol/IEQ). The HN-1 group (n = 5) had significantly higher ATP content compared with the UW group (n = 5) (p < 0.01). Data are expressed as the mean ± SE.

Figure 3

Evaluation of purified islet quality of each group in vivo. Normoglycemic percentage of STZ-induced diabetic nude mice after islet transplantation. A total of 1,500 IEQs were transplanted below the kidney capsule of diabetic nude mice. Normoglycemia was defined as two consecutive posttransplant blood glucose levels of less than 200 mg/dl. n = 10 for both groups.