Immunohystochemical study of the largest islets of human pancreas in aging and diabetes mellitus: perspectives for the transplantation

Abstract

Aim. To study the distribution and cellular architecture of the largest human pancreatic islets (with a diameter of more than 200 micron) in aging and diabetes mellitus types 1 and 2. Materials and methods. Antibodies to insulin, glucagon, somastatin and nturon-specific enolase were applied. The autopsy samples of the pancreatic tissue of patients with diabetes mellitus type 1 (DMT1) and type 2 (DMT2) and 2 age groups (up to 50 years old (control) and after 50 (aging control)), not suffering from diseases of the pancreas and carbohydrate metabolism malfunction were investigated. Results. The number of islets with diameter more than 200 mkm compared to control group increased both in aging and diabetes groups. Their number reaches in some cases 15% (and higher in DM) of the total number of islets. These islets compared to the other are rich-vascularized. It was shown that glucagon and somatostatin-containing cells are found both on the periphery of the large islets, and inside them only in the immediate proximity of the capillaries. Insulin-containing cells form clusters, surrounded by the capillaries and the ?- and ?-cells, while the inner part of such clusters has no direct contact with the capillaries. In the large islets the number of glucagon-containing cells is often increased, and insulin-containing cells show signs of degradation. Conclusion. The largest of the pancreatic islets may be useless for the transplantation, because of the high content of glucagon-containing cells, the rich vascularization and, in some cases, the limited functionality of ?-cells.

Keywords

• islets
• diabetes mellitus
• aging
• insulin
• glucagon
• somatostatin
• neuron-specific enolase
• nse
• transplantation