Histomorphological Study of the Pancreas between the Iraqi Squirrel (Sciurus anomalus) and Syrian Hamster (Mesocricetus auratus)

Abstract

Background: Rodents are commonly used as experimental models in pancreatic research. However, there is limited data regarding the comparison of the pancreas between the Iraqi squirrel and the Syrian hamster, which restricts our understanding of their physiological differences and potential implications for research. Aims: The study aims to investigate the histomorphological variances between the pancreas in the Iraqi squirrel and the Syrian hamster. Tissue samples were collected from the pancreas of four healthy adult Iraqi wild squirrels and four healthy adult Syrian hamsters. Pancreatic tissue was analyzed using hematoxylin and eosin, the periodic acid-Schiff, and Masson’s trichrome. In addition, the areas of the 40 islet Langerhans for each species were computed and analyzed (8 pancreatic tissues, 5 samples per tissue). Results: The anatomical results revealed a diffuse and more visible structure in the squirrel pancreas compared to the hamster. In contrast, the hamster pancreas exhibited a distinct and well-defined lobular organization. The pancreas of these two models has three main lobes. The histochemical analysis revealed pancreatic islets with a distinct structure, differentiated from the surrounding acinar cells. Furthermore, the squirrel pancreas exhibited a more pronounced organization of acinar cells and islets of Langerhans compared to the hamster. Quantitatively, no statistically significant differences in pancreatic islet area were observed within the same species. Conversely, the pancreatic islets of a squirrel have a significantly larger area than those of a hamster. Conclusions: The findings provide an important anatomical and histological database for understanding the functional differences and similarities between the two species. Finally, this study supports the potential use of the Iraqi squirrel as a comparative model.