大麻二酚对应激性心肌损伤的预防及其机制

目的:探索应激性心肌损伤之后,大鼠心肌组织及心肌细胞的状态和可能的作用机制.方法:采用水浸束缚应激的方式,建立大鼠应激性心肌损伤模型,观测大麻二酚治疗之后应激大鼠心率和血压的变化,血清中CORT、BNP、c-TnI、TNF-α和Il-1β的含量变化,以及应激前后心肌组织中mRNA的差异表达,将差异表达最显著的前100位...

Prevention of stress-induced myocardial injury by cannabidiol and its potential mechanism

OBJECTIVE To explore the status and potential mechanisms of myocardial tissue and cardiomyocytes in rats after stress-induced myocardial injury.METHODS The rat model of stress-induced myocardial injury was established by restraint stress of water immersion.The changes of heart rate(HR)and blood pressure(BP)after cannabidiol treatment and the altered serum levels of corticosterone(CORT),brain natriuretic peptide(BNP),cardiac troponin I(c-TnI),tumor necrosis factor-alpha(TNF-α)and interleukin-1β(Il-1β)were recorded.The differential expressions of mRNA in myocardial tissue before and after stress were observed.Top 100 genes with the most significant differential gene expression were classified according to oxidative and antioxidant effects.Hematoxylin-eosin(HE)stain and immunohistochemistry were employed for observing the effects of cannabidiol on stress myocardial injury;Western blot for examining the differential protein expression in cardiomyocytes after stress myocardial injury. RESULTS The rat model of stress-induced myocardial injury was verified by HE staining,immunohistochemical and biochemical enzymatic assays.HR and BP(P<0.05),serum CORT(P<0.05),BNP(P<0.05),c-TnI(P<0.05),TNF-α(P<0.05)and Il-1β(P<0.01)increased markedly.After a pretreatment of cannabidiol,HR(P<0.05),BP(P<0.01),serum CORT(P<0.001),c-TnI(P<0.001),TNF-α(P<0.01)and Il-1β(P<0.05)declined markedly.The transcriptome showed that top 100 genes with the most significant differential gene expression included 44 genes with oxidative effects and 34 genes with antioxidant effects.In vitro studies revealed that malondialdehyde(MDA)content spiked greatly in cardiomyocytes after stress(P<0.01)while superoxide dismutase(SOD,P<0.01)and glutathione(GSH,P<0.01)decreased.After a pretreatment of cannabinol at a dose of 2.5 μmol·L^-1,MDA content declined markedly(P<0.01)while the levels of SOD(P<0.05)and GSH(P<0.01)dropped.Hoechst 33342 and Annexinv-FITC/PI were utilized for detecting apoptotic cells.The number of apoptotic cells spiked after stress while cannabinol pretreatment reduced apoptosis.Gsk3β/Bax protein expression was markedly up-regulated while Nrf2/Bcl2 protein expression down-regulated after stress;Gsk3β/Bax protein expression was markedly down-regulated while Nrf2/Bcl2 protein expression up-regulated after a pretreatment of cannabidiol. CONCLUSION Cannabidiol may prevent stress-induced myocardial injury in rats.And its mechanism of action is correlated with the reductions of Gsk3β and Bax expression and the elevations of Nrf2 and Bcl2 protein expression.