【摘要】 目的:观察电刺激延髓外侧网状核(LRN)对大鼠心包内辣椒素(IC)诱发心脏-躯体运动反射(CMR)的下行性抑制作用并探讨其作用机制。方法:22只雄性SD大鼠随机分为电刺激组、电刺激+鞘内注射3g.L-1育亨宾组、电刺激+鞘内注射5g.L-1育亨宾组和电刺激+鞘内注射溶媒组,观察各组处理因素干预后大鼠IC诱发CMR的脊斜方肌肌电(EMG)的变化。结果:与对照组比较,电刺激(10、20和30μA)LRN能够抑制EMG,随着刺激强度的增加,抑制效果也加强,EMG分别下降到对照组的51.41%、21.11%和1.43%,(P<0.001),同时伴有或不伴有血压的改变;与电刺激组比较(10μA),鞘内注射肾上腺素能α2受体拮抗剂育亨宾(3和5g.L-1)部分逆转了电刺激LRN对CMR的抑制作用,EMG从41.34%分别升高到72.40%和78.73%(P<0.01)。结论:电刺激LRN对CMR具有下行性抑制作用,脊髓水平的α2受体参与了其抑制作用。更多还原

【Abstract】 Objective To study the descending inhibitory effect of the lateral reticular nucleus(LRN) treated with electrical stimulation on the cardiosomatic motor reflex(CMR) induced by intrapericardial capsaicin(IC) in rats and its mechanism.Methods 22 male SD rats were randomly divided into electrical stimulation group(n=7),electrical stimulation plus 3 g·L-1 yohimbine group(n=5),electrical stimulation plus 5 g·L-1 yohimbine group(n=5) and electrical stimulation plus vehicle group(n=5).The electromyogram(EMG) changes of dorsal spinotrapezius muscle of CMR induced by IC of rats were observed following intervention with treatment factors in various groups.Results Compared with control group,EMG could be inhibited by electrical stimulation of 10,20 and 30 μA in LRN,the inhibitory effect was increased with the increasing of the electrical stimulation intensity accompanied or not accompanied with changes of blood pressure;the EMG reduced to 51.41%,21.11% and 1.43% of the control(P<0.001);Compared with electrical stimulation(10 μA) group,intrathecal injection of adrenergic α2 receptor antagonist yohimbine(3 and 5 g·L-1) reversed the inhibitory effects of LRN stimulation on CMR,the EMG responses increased from 41.34% to 72.40% and 78.73%,respectively(P<0.01).Conclusion Electrical stimulation of LRN can produce descending inhibition on CMR and α2-adrenoceptors at spinal cord level may be involved in the inhibition.更多还原