Massive isolation, morphological and functional characterization, and xenotransplantation of XXXX pancreatic islets.

@entity1 @entity8788 @entity2544 @entity1943 @entity369 @entity291 @entity413 @entity6137
The limited availability of @entity1 donors makes the search for alternative islet sources mandatory for future developments in pancreatic islet transplantation. In this study, we report on the massive isolation of @entity291 islets of proven in vitro and in vivo viability. The islets were prepared by collagenase digestion, sequential filtrations, and density-gradient purification by modifying a technique previously developed in our laboratory for the porcine pancreas. The prepurification yield was 2,743 +/- 78 islet equivalents (IE)/g pancreas (mean +/- SE), with a postpurification recovery of 78.7 +/- 2.2%. Purity ranged from 80 to 90%. The histological and immunocytochemical studies demonstrated the identity and integrity of the islets with well-preserved @entity8788 -, glucagon-, and @entity1943 -containing cells. The morphological integrity of cultured @entity291 islets was demonstrated for up to 4 weeks from isolation. @entity8788 secretion from freshly isolated islets was similar at 3.3 mmol/l @entity413 (0.36 +/- 0.06 pmol.IE-1.min-1) and at 14 mmol/l @entity413 (0.42 +/- 0.00 pmol.IE-1.min-1), and it increased significantly (P < 0.01) at 25 mmol/l @entity413 (1.44 +/- 0.12 pmol.IE-1.min-1). @entity369 , @entity2544 , and @entity6137 increased @entity8788 secretion from freshly isolated islets at 3.3 and 14 mmol/l @entity413 , but not at 25 mmol/l @entity413 . Islets cultured at 37 degrees C in CMRL 1066 culture medium for at least 10 days were shown to become responsive to a lower @entity413 concentration, as demonstrated by the significant increase of @entity8788 release in response to 14 mmol/l @entity413 , when compared with basal secretion. This recovered responsivity to @entity413 was maintained after 4 weeks of culture.(ABSTRACT TRUNCATED AT 250 WORDS)
