运动神经肌肉电刺激对鼠骨骼肌微血管灌流的影响

在80年代初期,有文献报道应用神经肌肉电刺激(NMES)能改变周围血流动力学,并显示供给受刺激肌肉的动脉血流增加,未受刺激肢体的动脉血流减少,但并不了解其微血管床的具体反应.血流量与血流速度和灌流血管的横截面积成正比,但血流速度不能反应血液与实质组织的空间关系,而灌流血管的横截面积或微血管灌流程度可指示扩散距离、血液和实质组织的空间关系。肌肉微血管灌流程度是实质组织的氧、营养物质和代谢物的扩散距离为指示物,微血管灌流增加,则扩散距离减少,因而提高肌肉对氧、营养物质的利用,并提高代谢产物的清除率。

银杏叶提取物对大鼠应激性溃疡的保护作用

目的 探讨银杏叶提取物（ＥＧｂ） 对大鼠应激性胃溃疡发生的保护作用．方法 ♂ Ｗｉｓｔａｒ 大鼠，随机分成对照组、模型组和ＥＧｂ 处理组；通过胃窦部埋置电极记录束缚水浸应激过程胃平滑肌电活动变化，同时测定血浆和胃粘膜组织中丙二醛（ ＭＤＡ） 水平及观察胃粘膜的病理改变情况．结果 应激模型组大鼠胃电活动节律明显紊乱、慢波振幅和峰电位发放率较对照组显著增加，ＭＤＡ 显著升高（ Ｐ＜ ０－０５） ，并伴有胃粘膜广泛充血、溃疡；ＥＧｂ １５ ｍ ｇ／ ｋｇ 腹腔注射预处理可显著压抑（ Ｐ＜ ０－０１） 应激过程的胃电紊乱、降低 ＭＤＡ 水平和胃粘膜溃疡指数．结论 ＥＧｂ 对束缚水浸应激引起的胃运动功能障碍和胃粘膜溃疡有明显地保护作用，其机制可能是通过调整平滑肌电活动和对自由基的清除．

Antiarrhythmic Efficacy of Neferine Assessed by Programmed Electrical Stimulation in a Canine Model of Electropharmacology

An ishemic ventricular tachyarrhythmias canine model was established in open-chest dogs subjected to programmed electrical stimulation (PES)for 5-8 days after acute myocardial infarction. The electrophysiologic effects of neferine (Nef) and procainamide (PA) were observed in this model. With routine methods of PES,ventricular tachycardia (VT)and ventricular fibrillation (VF) could be reproducibly initiated. Both drugs lengthened the QTc interval (P【0.01) and effective refractory period(ERP)of normal and ischemic ventricular myocardia (NERP and IERP) respectively (P【0.01), decreased the dispersion of ERP in ischemic myocardium and the dispersion of ERP in left ventricle (P【0.01), and increased the diastolic excitability threshold of normal and ischemic ventricular myocardia (P【0.01). The two compounds prevented the PES-induced VT or VF (Nef group P【0.01, PA group P【0.05) and ischemia-induced VF (P【0.05). The results indicated that neferine and procainamide may be effective in preventing the onset of reentrant ventricular tachyarrhythmias after myocardial ischemic damage in dogs.

Electrophysiologic-electropharmacologic Method for Evaluating the Effects of Antagonizing Ventricular Tachyarrhythmic Drugs

Objective To establish a canine model of electrophysiologic - electropharmacology as assessed by programmed electrical stimulation (PES),and to observe the electrophysiologic effects of Procainamide(PA) on normal and ischemic myocardium in case of ischemic ventricular tachyarrhythmia in this model. Methods A ishemic ventricular tachyarrhythmias canine model was established in open-chest dogs subjected to programmed electrical stimulation(PES)for 5-8 days after acute myocardial infarction. The electrophysiologic effects of procainamide were observed in this model. With routine methods of PES,ventricular tachycardia(VT) and ventricular fibrillation (VF) could be reproducibly initiated. Results Procainamide distinctly lengthened the QTc interval (P【0.01) and effective refractory period(ERP) of normal and ischemic ventricular myocardium(NERP and IERP) respectively (P【0.01), decreased the dispersion of ERP in ischemic myocardium and the dispersion of ERP in left ventricle (P【0.01), and increased the diastolic excitability threshold of normal and ischemic ventricular myocardium remarkably (P【0.01). Procainamide effectively prevented the PES-induced VT or VF (P【0.05) and ischemia-induced VF (P【0.05). Conclusion The results indicated that PES-induced VT/VF were highly reproducible and reliable, this canine model is a worthy and reliable one, procainamide may be effective in preventing the onset of VT and VF after myocardial ischemic damage, and deserves further attention as an antifibrillatory agent.

Electrophysiologic Effects of Sophoridine on a Canine Model of Ischemic Ventricular Tachyarrhythmias

A canine model of ischemic ventricular tachyarrhythmias was established in open-chest dogs subjected to programmed electrical stimulation (PES) for 5￣8 days after acute myocardial infarction. The electrophysiologic effects of sophoridine (Sop) and procainamide (PA) were observed in this canine model. With routine methods of PES, ventricular tachycardia (VT) and ventricular fibrilation (VF) could be reproducibly initiated in this model. Both drugs distinctly lengthened the QTc interval ( P <0.01) and the effective refractory period (ERP) in normal and ischemic ventricular myocardium ( P <0.01), decreased the dispersion of ERP in ischemic myocardium and the dispersion of ERP in left ventricle (P <0.05), and increased the diastolic excitability threshold of normal and ischemic ventricular myocardium remarkably ( P <0.01). Both drugs effectively prevented the PES-induced VT or VF and ischemia-induced VF ( P <0.05). The results indicated that this canine model is a good and reliable one, sophoridine and procainamide may be effective in preventing the onset of reentrant ventricular tachyarrhythmias after myocardial ischemic damage.

The distribution of motilin receptor in the amygdala of rats and its role in migrating myoelectric complex

Objective:To investigate the distribution of the motilin receptor in the amygdala of rats and its role in regulating the duodenal migrating myoelectric complex(MMC).Methods:The distribution of motilin receptor in the amygdala in adult SD rats was detected by immunohistochemistry methods,and the duodenal interdigestive MMC was recorded via the electrodes implanted in the duodenum and analyzed us- ing a multichannel recorder.Results:Motilin receptor was observed in the amygdala of rats.The great amount of motilin receptor was found in the medial amygdaloid nucleus,which was also abundant in the basolateral nucleus but less abundant in the basomedial amygdaloid nucleus,the central amygdaloid nucle- us and the lateral amygdaloid nucleus.The shortening of the duodenal MMC cycle duration and the in- crease of the amplitude and the frequency of phase $ were recorded after motilin receptors being bound with exogenous motilin in the amygdala.The effects could be completely blocked by the subdiaphragmatic vagotomy but not by the intravenous injections of atropine,phentolamine or propranolol.Anti-motilin serum could partially block these effects,and the destruction of the basolateral nucleus of the amygdala had no significant effects on the duodenal MMC.Conclusion:Motilin receptor is present in all the subnu- clei of the amygdala,with the greatest amount of motilin receptor present in the medial amygdaloid nucle- us.Microinjections of motilin in the amygdala can shorten the duodenal MMC cycle duration and increase the amplitude and the frequency of phaseⅢ.These effects might be accomplished via the amygdala-hy- pothalamus-brainstem-vagus pathway,indicating the important role of the amygdala motilin receptor in the duodenal MMC regulation.

CLINICAL SIGNIFICANCE OF COMPLETE LEFT BUNDLE BRANCH BLOCK IN DILATED CARDIOMYOPATHY

Clinical, electrocardiographic and echocardiographic findings in 64 patients with dilated cardiomyopathy were retrospectively studied. Compared with 51 patients without complete left bundle branch block (CLBBB), 13 patients with CLBBB had higher New York Heart Association (NYHA) functional class (P<0. 05), increased left ventricular end-diastolic and end-systolic diameters (P<0. 002) and myocardial mass (P<0. 02). severe mitral regurgitation (P<0. 01) and higher mortality rate (P<0. 04). Multivariate stepwise regression analysis revealed that the presence of CLBBB was an independent prognostic factor for patients with dilated cardiomyopathy.