title: The distribution of porcine pancreatic beta-cells at ages 5, 12 and 24 weeks.
abstract: Islet transplantation is a potential treatment for diabetes mellitus and porcine pancreata may provide a readily available source of islets. The size, number and distribution of islets within the pancreas may influence the choice of age of donor for xenotransplantation. Samples (n = 3 per age group) from the dorsal and ventral pancreas of 5-, 12- and 24-week-old hybrid pigs were fixed in formal saline, processed in paraffin wax and stained with an avidin/biotin immunohistochemical kit for insulin, glucagon, somatostatin and pancreatic polypeptide. The arrangement of endocrine cells within the pancreata were studied and mean diameter of beta-cell groups were measured (from insulin stained sections) in 1 mm2 grid areas (n = 10 per section) and collated into groups according to size. Percentage volume density of beta-cells in relation to the whole pancreas was calculated and also the distribution of beta-cell groups, according to their size, within the total beta-cell mass. There were differences in the frequency and arrangement of endocrine cells within islets at the different ages studied. beta-Cell groups < 50 microm in diameter occupied 70 to 80% of the total beta-cell mass at 5 weeks but, as the age of the pig increased, larger cell groups were more abundant. However, the percentage volume density of beta-cells within the total pancreas did not change as the pancreas matured. This study shows that the endocrine porcine pancreas was maturing and its structure changed between the ages of 5 and 24 weeks. The relevance of these findings may have implications on the isolation and function of islets if young pigs are to be used as donors for transplantation as a treatment for diabetes mellitus.
authors.affiliation: Islet Research Laboratory, Worcester Royal Infirmary NHS Trust, UK.
authors.forename: T R
authors.initials: TR
authors.lastname: Jay
authors.forename: K A
authors.initials: KA
authors.lastname: Heald
authors.forename: N J
authors.initials: NJ
authors.lastname: Carless
authors.forename: D E
authors.initials: DE
authors.lastname: Topham
authors.forename: R
authors.initials: R
authors.lastname: Downing
mesh_terms: D000375:Aging; D000818:Animals; D003920:Diabetes Mellitus / Q000628:therapy; D006801:Humans; D007515:Islets of Langerhans / Q000166:cytology*; D016381:Islets of Langerhans Transplantation; D010179:Pancreas / Q000166:cytology* / Q000502:physiology; D013552:Swine; D014183:Transplantation, Heterologous