Streptozotocin and high-fat diet induced insulin abnormalities after six weeks of feeding. (A) Insulin tolerance test. Blood glucose was measured 15, 30 and 60 min after insulin injection. n = 10, * p < 0.05 vs. ND/CITRATE. (B) Insulin secretion in response of glucose ingestion. n = 5, *p < 0.05 compared to fasted conditions, † p < 0.05 HFD/CITRATE vs. ND/CITRATE. (C) Immunohistochemistry of pancreas using an anti-insulin antibody. Arrows indicate cells with lower staining intensity. Magnifications were ×100 and ×400, as indicated.