| 1 | Taxol inhibits stretch-induced electrophysiological alterations in isolated rat hearts with acute myocardial infarction显示文摘Mechanosensitive channels have been determined to work as transducers of mechanoelectric feedback in the heart, which is associated with the generation of arrhythmias. Recent studies have investigated the role of the cytoskeleton in ion channels control. This study explored the ability of taxol to inhibit stretch-induced electrophysiological alterations in the ischemic myocardium. Thirty-two Wistar rats were randomly divided into four groups: normal control group (n=9), taxol group (n=7), myocardial infarction (MI) group (n=9), and MI+taxol group (n=7). After Langendorff perfusion, the isolated hearts were stretched for 5 s by balloon inflation to 0.2 or 0.3 mL. The effects of stretching on 90% monophasic action potential duration (MAPD90), premature ventricular beats (PVB), and ventricular tachycardia (VT) were observed for 30 s. Stretching increased MAPD90 in both the normal control and MI groups, but MAPD90 increased more in the MI group for the same degree of stretch. Taxol (5 μmol L?1) had no effect on MAPD90 under baseline, unstretched conditions, but MAPD90 in the taxol group was slightly increased after stretching compared with the normal control group (P>0.05). However, taxol reduced MAPD90 in infarcted myocardium (P<0.05 at V=0.3 mL). The incidences of PVB and VT in the MI group were higher than in the normal control group (both P<0.01). Taxol had no effect on the occurrence of arrhythmias in normal myocardium, but it inhibited PVB and VT in infarcted hearts (both P<0.01). Thus changes in MAPD and the occurrence of arrhythmias caused by mechanical stretching of the myocardium could be inhibited by taxol in isolated rat hearts during AMI, indicating the involvement of tubulin in mechanoelectric feedback in AMI. | CAO JunXian1, FU Lu1, SUN DianJun2, XIE RongSheng1, ZHOU Jue3 & QU Fan4 1Department of Cardiology, The First Affiliated Hospital of Harbin Medical University, Harbin 150001, China 2Chinese Research Center for Endemic Disease Control, Key Laboratory of Etiological Epidemiology, Ministry of Health (23618504), Harbin Medical University, Harbin 150081, China 3Pharmacy Department, King’s College London, Franklin-Wilkins Building, 150 Stamford Street, London, UK 4The First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou 310003, China | 2010 | Science China(Life Sciences)2010，53，8： | 2 |
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