ORGAN-CULTURE OF FETAL PIG PANCREAS FOR TRANSPLANTATION

The isolation of islets of Langerhans from the fetal pancreas in vitro may be an effective way of harvesting tissue for transplantation in i nsulin-dependent diabetes mellitus. Fetal pancreas has the advantage o f also containing many islet precursor cells and their preservation ma y increase the pool of potentially functional cells that can develop a fter transplantation. Short-term organ culture of fetal pig pancreatic fragments selectively eliminates non-endocrine cells whereas endocrin e cells, and their precursors, are preserved, This paper documents the development of the tissue in vitro under two different culture condit ions, Culture in 90%O-2/10%CO2 (''HiO(2)'') was compared to convention al culture (''CC'') in 10%CO2/90% air (similar to 20%O-2), HiO(2) prev ents ischaemic central necrosis of the tissue fragments and increases islet yield, but prolonged exposure to 90%O-2 leads to generalised cel l. death affecting both exocrine and endocrine components; this cannot be prevented by the addition of the oxygen free radical scavengers, n icotinamide and catalase, The amount of insulin, glucagon and somatost atin containing cells in the fetal pig pancreas appeared not to be aff ected by the different culture conditions as revealed by immunoperoxid ase staining, To determine whether islet precursor cells could be dete cted in the ducts, in situ hybridisation was used to search for pre-pr o-insulin mRNA, This was however, only detectable in maturing or matur e beta-cells that already contained insulin detectable by immunoperoxi dase cytochemistry but not in the putative immature endocrine precurso rs in the pancreatic ducts.