A BRIEF COMMUNICATION

In 2004, the human islet amyloid polypeptide (HIP) rat model was created by transfecting the Sprague-Dawley rat with the human islet amyloid polypeptide (hIAPP)-amylin gene. The objective of this study is to utilize the transmission electron microscope to study the longitudinal cellular and extracellular morphological changes within the islets of this model at 4, 8, and 14 months of age. It has been previously demonstrated that the 2-, 5-, and 10-month HIP models have no diabetes, impaired fasting glucose, and diabetes, respectively. The 4-month HIP model (FBS 123 mg/dl) demonstrated an abundance of β-cells and insulin secretory granules with significant pericapillary and inter-β-cell islet amyloid deposition. The 8-month model (FBS 187 mg/dl) demonstrated extensive islet amyloid deposition and marked changes of β-cell apoptosis. The 14-month-old model (FBS 244 mg/dl) demonstrated islet and β-cell atrophy with even greater amounts of extracellular islet amyloid compared to the 4-month-old and 8-month-old ...