Downregulation of Kir6.1/SUR2B channels in the obese rat aorta

Abstract

Objective This study was designed to evaluate the contribution of adenosine triphosphate–dependent potassium channels to the increase in blood pressure observed in obese rats. Methods The experiment was performed in male Sprague-Dawley rats. Glibenclamide-sensitive currents were measured in vascular smooth muscle cells by patch-clamp. Expressions of Kir6.1 and SUR2B were examined by reverse transcription polymerase chain reaction and western blot techniques, respectively. Results In the aortic vascular smooth muscle cells, pinacidil induced glibenclamide-sensitive currents. The current from obese rats was significantly lower (−10.55 ± 1.63 pA/pF) compared with that from the control rats (−20.18 ± 2.79 pA/pF). Expressions of Kir6.1 and SUR2B were downregulated in vascular smooth muscle cells of aortas from the obese rats. Conclusion These findings suggest that the adenosine triphosphate–dependent potassium channel is downregulated in smooth muscle cells from the aortas of obese rats, which may contribute to the increase in blood pressure in these rats.