Comparison of the Efficacy of Available Collagenases on Human Islet Isolation From Research Grade Pancreata

Abstract

Results:The mean (± SD) collagen content in the adult group was 5.9 ± 1.8% (range 2.3-11.0), this was signifi cant higher (p<0.001) than in the juvenile group where the mean collagen content was 3.7 ± 1.3% (range 1.1-7.1). Apparently, the pancreas undergoes a process of fi brosis as pigs grow older. This was confi rmed by a signifi cant correlation between collagen content and age in the overall group (r=0.33, p<0.001). In a pancreas, an average of 80.7 ± 16.4% of the islets was encapsulated less than 50%. However, this average ranged from 23 -100%, showing high variability in islet encapsulation between pancreases. Between total collagen content and islet encapsulation a signifi cant positive correlation (r=0.33, p<0.05) was found, indicating that in pancreases with high total collagen content, a larger number of islets are encapsulated greater than 50%. After isolation and purifi cation, the average obtained islet yield was 545.4 ± 601.2 IE/g pancreas (range 18-3849). We found no signifi cant correlation between collagen content and obtained islet yield (r =-0.004, p=0.98). Furthermore, no signifi cant correlation was found between the percentage of islet encapsulation in each pancreas and obtained islet yield (r=-0.053, p=0.69). Conclusions: Neither the amount of collagen nor the islet encapsulation have effect on porcine islet isolation outcome. Possibly the amount and distribution of collagen subtypes (e.g. collagen type VI), rather than the total content, can explain some of the variability in porcine islet isolation.