Protective Effects Of Gastrodin On Myocardial Ischemia Reperfusion Injury In Rats By Preconditioning

IntroductionMyocardial ischemia reperfusion injury (MIRI) is often occured after the diseases of cardiovascular system such as the mitigation of coronary artery spasm, embolization recanalization of cardiovascular and organ traMIRIplantation and so on. MIRI is involved in the growth of the oxygen free radicals (OFR), calcium overload and other pathological process. Gastrodin is one of the effective components of Gastrodia elata, which can protect the heart by increasing the blood flow of the coronary vessels. There has not been reported at home and abroad about the protective effects of Gastrodin on Myocardial Ischemia Reperfusion Injury in Rats by Preconditioning.ObjectiveTo establish the MIRI model of rats. To investigate the protective effects of Gastrodin on myocardial ischemia reperfusion injury in Rats by preconditioning and parts of mechanisms of Gastrodin.MethodsSD rats were randomized into sham group, MIRI group, Gastrodin group of low dose (100mg/kg), middle dose (200mg/kg) and high dose (400mg/kg), and Verapamil group (20mg/kg). The MIRI model of rats was established by ligaturing the left anterior descending coronary artery. The effects of Gastrodin on MIRI rats by preconditioning were estimated with the occurence of the arrhythmia, serum enzyme and histomorphology and its mechanisms were studied with the myocardial cell bioelectricities and calcium imaging techniques.Rats were treated via intragastric administration for one week. MIRI model was established. Monitor the occurence of the arrhythmia by electrocardiogram recording. Serum kinases such as CK-MB, LDH, SOD, and MDA were detected according to the kit MIRI introduction. The tissues of left ventricular anterior wall were taken to observethe changes in myocardial histology and morphology by HE staining.To observe the the effects of Gastrodin on the sinoatrial node cells and atrial myocytes by the myocardial cell bioelectricities techniques. To observe the the effects of Gastrodin on the calcium influx by calcium imaging techniques.All statistical analysis was performed using SPSS17.0software. Comparison between groups used ndependent sample t-test in measurement data which was showed as x±sd. Comparison between groups used two sample rates Chi-square in Count data.Results1. The effect of Gastrodin on the heart rate and occurence of the arrhythmia. Compared with the sham group, the heart rate of was accelerated obviously in Gastrodin group of middle and high dose (P<0.05).Compared with the sham group, the incidence of the arrhythmia after MIRI was increased in the MIRI group (P<0.01). Compared with the MIRI group, the incidence of the arrhythmia after MIRI was reduced in Gastrodin group of middle and high dose and Verapamil group (P<0.05). 2. The effect of Gastrodin on LDH and CK-MB in serum. Compared with the sham group, LDH and CK-MB in serum were increased obviously in the MIRI group (P<0.01). Compared with the MIRI group, LDH and CK-MB in serum were reduced significantly in Gastrodin group of middle and high dose and Verapamil group (P<0.05).3. The effect of Gastrodin on SOD and MDA in serum. Compared with the sham group, SOD in serum was reduced in MIRI group (P<0.05). Compared with the MIRI group, SOD in serum was increased in Gastrodin and Verapamil group (P<0.05). Compared with the sham group, MDA was increased obviously (P<0.01) in the MIRI group. Compared with the MIRI group, MDA in serum was reduced in Gastrodin group of middle and high dose and Verapamil group (P<0.05).4. The effect of Gastrodin on the histology and morphology. Compared with the sham group, the myocardial cells were misaligned, cross striations and boundaries dimmed. Cytoplasm and nucleus were uneven colouring. The cells were obviously dropsical. A large number of red blood cells and inflammatory cells infiltrated and angiotelectasis were observed in the MIRI group. Compared with the MIRI group, the myocardial cells arrangement were neat, the cross striations and boundaries were clear, the cytoplasm and nucleus were even colouring, the cells were not obviously dropsical, and there were a small number of red blood cells and inflammatory cells infiltrated in the Gastrodin group of middle and high concentration and Verapamil group5. The membrane potential recordings of sinoatrial node cells and atrial myocytes. Compared with the Pre-Gastrodin group, Gastrodin (20μmol·L-1) significantly accelerated Vmax4of sinoatrial node cells and shortened APD90of atrial myocytes (P<0.05) and they were recovered after washing out..6. Store-operated Ca2+influx detection. Compared with the sham group, the degree of fluorescence inteMIRIity decreased after CaCl2(2.5μmol/L) applying in Gastrodin group (P<0.05).Conclusion1. Gastrodin has protective effects on MIRI in rats by preconditioning.2. The protective effects of Gastrodin on ischemia reperfusion injury are related to inhance the SOD, lighten inflammatory cell infiltration and inhibit Ca2+influx.3. The effects of Gastrodin may be related to accelerate self-discipline of the sinoatrial node cells and shorten action potential time of atrial myocytes.