Pancreatic Beta Cell Proliferation in Rabbits Demonstrated by Bromodeoxyuridine Labeling

Abstract

The purpose of the present study was to quantify beta cell proliferation in rabbits that had undergone subtotal beta cell ablation by labeling cell nuclei undergoing DNA synthesis with bromodeoxyuridine (BUdR). Ten New Zealand white rabbits were compared with five sham-operated controls. The beta cells in the head of the pancreas were destroyed by intravenous alloxan (200 mg/kg) while the tail of the pancreas was temporarily isolated from the systemic circulation by vascular occlusion clamps. On day 7, BUdR (70 mg/kg) was infused prior to killing to label newly synthesised DNA. Immunoperoxidase staining with anti-insulin sera and an anti-islet cell monoclonal antibody confirmed the absence of insulin-producing cells in the head of the pancreas. Beta cell proliferation within the islets of the tail of the pancreas was suggested by the appearance of cells undergoing mitosis and confirmed by BUdR labeling of cell nuclei detected with anti-BUdR monoclonal antibody. The mitotic index was significantly increased compared to control rabbits (p = 0.0235, Mann-Whitney U nonparametric test). This study demonstrates that the BUdR labeling can be used to document beta cell proliferation in vivo in the rabbit model after subtotal beta cell ablation.