兔离体十二指肠平滑肌细胞电活动与肌收缩活动关系

Relations of electrical and mechanical activity on duodenal smooth muscle strip in rabbits

本工作采用玻璃微电极记录兔离休十二指肠平滑肌细胞内电变化，并同步记录兔离休平滑肌条的收缩，从而分析慢波，前电位和动作电位与肌收缩的关系。结果表明：（１）慢波能引起兔十二指肠近端平滑肌收缩，并呈１：１的关系；（２）在慢波引起肌收缩的基础上，前电位可使肌收缩进一步加强；（３）兔十二指肠近端的平滑肌自发放电产生的动作电位，其幅度为５２．１±８．５ｍｖ（ｎ＝３０），在形式上有的呈单一放电，有的呈簇状放电，前者放电频率为１～４次／秒，后者为６次／秒；（４）三种电活动引起肌条收缩的幅度以动作电位最大，前电位次之，慢波最小。上述资料表明，兴奋性高的兔十二指肠近端的平滑肌细胞内不同的电活动可引起不同的收缩。

The electrical and mechanical activity of the duodenal smooth muscle strip were recorded simultaneously with intracellular micro-electodes and the mechano-electronic transducer. The relations of them were observed and analysed.The results were as follows:(1)The slow wave could induce duodenal smoorh muscle strip contraction,and there were 1:1 pattern between them.(2) The prepotential could induce further contraction of the muscle strip induced by the slow wave.(3) The amplitude of action potential discharged from duodenal smooth muscle strip was 52.1±8.5 mV.There were unitary and cluster of discharges,the frequency of unitary discharge was 1-4 imp/s,of cluster discharge was 6 imp/s.(4) The intensity of muscle contraction resulted in from slow wave,prepotential and action potential had following relation:slow wave<prepotential<action potential.The results suggested that the different electrical activities of duodenal smooth muscle cell could induce various intensities of contraction.