A light-microscopic immunocytochemical study of the endocrine pancreas in the Australian fat-tailed dunnart (Sminthopsis crassicaudata).

The endocrine pancreas of the Australian fat-tailed dunnart (Sminthopsis crassicaudata) was investigated by means of immunocytochemistry using the avidin-biotin-peroxidase technique. This was a light microscopic study using this established technique and has not been previously investigated. Serial paraffin sections were stained individually with primary antibodies for anti-porcine glucagon, anti-beef pork insulin, anti-human somatostatin, and anti-avian pancreatic polypeptide (APP), anti-bovine pancreatic polypeptide (BPP), anti-serotonin, anti-porcine motilin, showing the same islet. Cells immunoreactive to porcine glucagon, porcine insulin, human somatostatin, APP, BPP were found in endocrine islets, but BPP and APP also appear to be scattered amidst the exocrine portion. Immunoreactive cells were not observed with serotonin and anti-porcine motilin. All controls were negative. These results in the dunnart pancreas has shown four types of pancreatic endocrine cells. It has also shown that the structure of PP may more closely resemble BPP than APP. This study can be related to studies in echidnas (Tachyglossus aculeatus) and Australian possum (Trichosurus vulpecula). This is a part of an immunocytochemical study investigating the endocrine pancreas in Australian mammals.