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.
ABSTRACT
Aim To study the effect of hesperdin and synephrine on the isolated gastric smooth muscle cells.Method Gain isolated gastric smooth muscle cells by digesting gastric smooth muscle with collagenase(typeⅡ), measure long axis length of 25～50 cells randomly under microscope. Then, compare the contraction change of cells between before and after given drugs, the contraction change of cells is expressed with percent, negative expresses contraction, positive expresses relaxation.Results Hesperdine had no effect on the isolated gastric smooth muscle cells. The contractile response to synephrine was prompt, rising to a peak within 60 s and dose-dependent at the range of 0.001～1 g?L -1. Synephrine inhibited the excited cells caused by acetylcholine(P