Detection of amyloid deposition in various regions of the feline pancreas by different staining techniques

Abstract

Deposition of islet amyloid is a common finding in the pancreas of diabetic cats and it may contribute to the deterioration of glucose tolerance. Three techniques for detecting pancreatic amyloid deposition were compared in cats not known to be diabetic. Congo red (CR) staining was used for histological sections (35 cats) and tissue smear preparations (crush and smear [CS] technique; 35 cats, and an immunohistochemical method (18 cats) was used for the detection of amyloid derived from amylin. Six diabetic cats were used as positive controls for the immunohistochemical method. The amount of pancreatic amyloid demonstrated immunohistochemically was significantly correlated with that shown by CR staining in histological sections but not in CS preparations, which were less satisfactory. However, the amount of amyloid determined immunohistochemically was slightly but significantly higher than that seen in CR-stained sections. There was no difference in the amount of amyloid between the left limb middle segment and right limb of the pancreas. Amylin labelling was seen in about 70 to 80% of islet cells, mainly those located in the islet periphery and the labelling was most intense in the cell periphery.