Pancreatic effects of diesel exhaust particles in mice with type 1 diabetes mellitus

Background/Aims: Epidemiologically, diabetics are more prone to the adverse health effects of particulate air pollution than healthy individuals. We recently demonstrated an increased cardiovascular and respiratory susceptibility to diesel exhaust particles (DEP) in mice with type 1 diabetes. However, the pancreatic effects of DEP in healthy and diabetic mice are unknown. Methods: Presently, we evaluated the pancreatic impact of DEP in healthy mice, and mice with streptozotocin-induced type 1 diabetes. Four weeks following induction of diabetes, mice were intratracheally instilled (i.t.) with either DEP (0.4 mg/kg) or saline, and several histological and biochemical endpoints were measured 24 h thereafter. Results: Neither the histology nor the stain for apoptosis in the pancreatic islets and exocrine glands were affected by DEP. In diabetic mice exposed to saline, the islet cells showed cellular vacuolation and apoptotic islet cells (71.6 ± 2.6%). In diabetic mice exposed to DEP, a more marked decrease in the size and number of islet cells with cellular vacuolation along with a significant increase of apoptotic islet cells (79.1 ± 1.7 %, P