短波胃电刺激对垂体后叶素所致呕吐样症状的作用

Effects of gastric electrical stimulation with short pulses on vasopressin-indcued emetic response in dogs

目的本文拟系统研究短脉冲和短波串脉冲胃电刺激对垂体后叶素所致犬呕吐样相关症状的作用。方法本文共研究了7条雌性Beagle犬,所有犬均于胃浆膜面埋植4对电极。实验随机分为4组。每组实验包括20分钟基础记录时间段、20分钟灌注垂体后叶素或盐水和另两个20分钟记录时间段。在1和2组中,盐水和垂体后叶素持续静脉滴注,不加胃电刺激。在3或4组中,垂体后叶素在第2个20分钟时间段灌注,胃电刺激(短脉冲:300μs,4mA,4IF;短波串脉冲:40Hz,6mA,0.3mswith3s开8s关)在前3个20分钟时间段中经由距幽门近端14cm处(第1对)电极给予。实验中记录胃慢波和呕吐样相关症状。结果①垂体后叶素能诱导胃电节律紊乱和呕吐样相关症状(ANOVA,P<0.001)。②短脉冲胃电刺激和短波串脉冲胃电刺激能减轻垂体后叶素所致呕吐样相关症状(P<0.001),但不能纠正胃电紊乱(P>0.05)。症状评分从垂体后叶素组14.7±1.4,减少至5.5±1.1(短脉冲胃电刺激组)和6.4±1.33(短波串脉冲胃电刺激组)。与垂体后叶素灌注不加电刺激比较(所有狗出现呕吐),短脉冲和短波串脉冲胃电刺激组中没有狗出现呕吐(P<0.001)。结论短脉冲和短波串脉冲胃电刺激能治疗呕吐样相关症状,而对胃电节律紊乱无作用。

Objective To investigate the effect of GES with short pulses or short-pulse trains on gastric dysrhythmia and motion-sickness symptoms induced by vasopressin in dogs. Methods Seven male beagle dogs implanted with 4 pairs of electrodes on gastric serosa were studied. The study was performed in four sessions in a randomized order. Each session was composed of 20-min baseline, 20-min infusion of vasopressin or saline, and two more than 20-min recordings. In session 1 or 2, either saline or vasopressin was infused without GES. In session 3 or 4, vasopressin was infused during the second 20-min period and GES was applied during the first three 20-min period via the electrodes 14 cm above the pylorus using with short pulses [300μs, 4mA, 4IF （intrinsic frequency of gastric slow waves）] or trains of short pulses （40 Hz, 6mA, and 0.3 ms with 3 s on and 8 s off）. Gastric slow waves and motion-sickness symptoms were recorded in each session. Results ①Vasopressin induced gastric dysrhythmia and motion sickness-like symptoms （ANOVA, P 〈 0.001 ）. ②GES with short pulses or trains of short pulses was capable of preventing vasopressin-induced emetic response （P 〈 0.001 ）,but did not normalize gastric dysrhythmia. The symptom score was significantly decreased from 14.7 ± 1.4 in the vasopressin session to 5.5 ± 1.1 or 6.4 ± 1.33 （P 〈 0.01） in session with GES of short pulse or trains of short pulses. Compared with the vasopressin session in which 6 out of 7 dogs had vomiting, none of 7 dogs experienced vomiting in session with GES of short pulses or trains of short pulses （P 〈 0.01 ）. Conclusion GES with short pulses or trains of short pulses prevents vasopressin-induced emetic response with no improvement of gastric dysrhythmia.