Free style freedom blood glucose monitoring system

Twenty female SPD rats weighing 200–250 g were used for the study of experimental T1DM. STZ (Sigma, St Louis, MI, USA) was dissolved in citrate buffer (pH, 4.5) and injected by a single intraperitoneal injection of 55 mg STZ/kg body weight to 10 of the animals. The remaining SPD rats were injected with saline and served as a control group. Whole blood tail glucose concentrations were measured between 9 am to 11 am, weekly using Free Style Freedom Blood Glucose Monitoring System (Abbott Laboratories, USA). Animals were considered diabetic at blood glucose level ≥ 250 mg/dL. PO and SPD rats were killed 20 and 10 days after development of diabetes, respectively. Following sacrifice, rat abdomens were quickly opened; the stomach was excised along the greater curvature, rinsed in saline, and longitudinally bisected. One-half of the stomach specimen was immediately frozen in liquid N₂ and kept at −70°C for mRNA extraction and analysis and the other half was immersed in formaldehyde for immunohistochemical analysis.

Intraperitoneal glucose tolerance tests (IPGTTs) were performed on 12-h fasted mice. Body weight and blood glucose (Freestyle Freedom Blood Glucose monitoring System, Abbott Laboratories) was measured prior to IP injection of glucose (Sigma-Aldrich) (1–2 g/kg body weight). Subsequent blood glucose measurements were performed at time 0 and at 20/30, 60, 90, 120 and 180 min post IP injection of the glucose bolus.