Effects of K
channel opener, diazoxide (DZ), on the heart rates in STZ-diabetic rats with 8 weeks of diabetes (closed circles) and Wistar rats (open circles). Diabetic rats were iv injected with DZ at 0.5, 1 or 2 mg/kg. Wistar rats were received same treatment with DZ at 3, 5 or 8 mg/kg. The results are expressed as the mean ± SE obtained from each group of 7 animals. * P < 0.05 and ** P < 0.01 for comparisons of the post-injection heart rates with the pre-injection baseline heart rate (0) in each group.