Changes of large-conductance calcium-activated potassium channel in gastric smooth muscle cells of diabetic gastroparesis rats / 中国病理生理杂志

ABSTRACT

[ ABSTRACT] AIM: To discuss the relevance between the pathogenesis of diabetic gastroparesis and the large-conductance calcium-activated potassium channels ( BKCa ) in gastric smooth muscle cells.METHODS:The SD rats were randomly divided into control group and model group.The gastric smooth muscle cells of the SD rats were enzymatically iso-lated in a low calcium solution containing papain.The current was recorded by patch clamp single channel recording tech-nique.The expression of KCNMA and KCNMB1 were observed by the method of immunohistochemistry.RESULTS:The value of BKCa single channel conductance was (220.10 ±10.90) pS;the channels had distinct voltage dependent and cal-cium dependent characteristics.In outside-out patch (Vm =+30 mV), the activation of BKCa was blocked by 200 nmol/L IbTX completely.Compared with control group, the open probability and amplitude of current in model group significant-ly increased, while the mean open time and mean close time significantly decreased.Compared with control group, the ex-pression of KCNMB1 in model group was significantly increased.CONCLUSION: Up-regulation of β1-subunit and in-crease in BKCa functional activities may be associated with diabetes gastroparesis in rats.