Anatomical and Stereological Analysis of Pancreatic Islet Cell Density in a Type 2 Diabetes Rat Model: Implications for the North Central Nigerian Population

Type 2 diabetes mellitus is a rapidly increasing metabolic disease in Nigeria, driven by urbanisation, dietary transition, and sedentary lifestyles. The pathological decline in pancreatic beta cell mass and islet cell density is a central anatomical feature of this condition, yet it has not been systematically characterised in experimental models relevant to North Central Nigerian nutritional patterns. This study aims to perform stereological and histological analysis of pancreatic islet cell density, beta cell area fraction, and islet morphology in a high-fat diet and streptozotocin-induced type 2 diabetes rat model. Sixty Wistar rats will be fed a high-fat diet for eight weeks, followed by a low-dose streptozotocin injection to induce a type 2 diabetic state, while controls receive standard diet and citrate buffer. Pancreatic sections will be immunostained for insulin to identify beta cells and glucagon for alpha cells. Beta cell mass, islet number per unit area, and individual islet size will be quantified using unbiased stereological probes. Fasting blood glucose and C-peptide levels will provide functional correlates. The study anticipates providing quantitative anatomical data on islet cell depletion relevant to understanding the histopathological basis of type 2 diabetes progression.

Keywords: pancreatic islets, beta cells, type 2 diabetes, stereology, high-fat diet