After 5 wk of treatment, SBP was measured by tail cuff plethysmography in each group based on an average of five readings per animal (ADI Instruments Inc., Colorado Springs, CO, USA) and registered with the ADI Instruments Program (Lab Chart Pro7.Ink). The rats were sacrificed by decapitation after light anesthesia with isoflurane. The blood was collected in a vacutainer tube early in the morning after fasting overnight (16 h) for plasma insulin determination. The aorta was removed and kept frozen at –20C until use.