STUDIES OF THE ISOLATION AND VIABILITY OF HUMAN ISLETS OF LANGERHANS1,2

Abstract

Pancreas obtained from 34 adult human cadaver organ donors was divided into proximal and distal segments, and the duct to each segment was cannulated. Collagenase was injected into the proximal duct of 7 glands and into the distal duct of 7 others; the duct of the opposite segment was perfused with collagenase. The pancreas was then dispersed by teasing, trituration, and passage through filters. Perfused proximal and distal segments released 1461 .+-. 287 and 2728 .+-. 797 islets/g (.+-.SEM) versus 710 .+-. 149 (P < 0.05) and 1950 .+-. 636 after injection. Twenty other pancreases were perfused with collagenase warmed rapidly to 39.degree. C (n=4) or warmed slowly to 37.degree. C (n=6) or 39.degree. C (n=10): the yield was 1625 .+-. 632, 1320 .+-. 116, and 2009 .+-. 277 islets/g respectively. Total yields from the latter were 76 .times. 103 large (>100 .mu.m) and 85 .+-. 103 small (6 hr and tissue obtained from multiple centers. Less insulin was produced by freshly isolated islets, islets <100 .mu.m, and after Ficoll separation. Secretion was similar for islets derived from proximal or distal segments. Perfusion of collagenase via the ducts of human pancreas improves islet isolation and Ficoll gradient separation yields highly purified islets. Important factors influencing insulin secretion are the source of donor tissue, cold storage of pancreas, Ficoll purification, islet size, and tissue culture.