Effect of total flavonoids of astragalus on endoplasmic reticulum chaperone, calumenin and connecxin 43 in suckling mouse myocardium with myocarditis caused by coxsackievirus B3 / 中国应用生理学杂志

<p><b>OBJECTIVE</b>To investigate the effect of total flavonoids of astragalus on the expression of endoplasmic reticulum chaperone, calumenin and connecxin 43 (CX43) in suckling mouse myocardium with myocarditis caused by coxsackievirus B3 (CVB3).</p><p><b>METHODS</b>The primary culture of suckling mouse myocardium cells were randomly divided into control group, CVB3 infected group and total flavonoids of astragalus group. Firstly, to confirm the identity of the suckling mouse myocardium, α-SMA was monitored by immunohistochemistry method. Then the protein expression changes of endoplasmic reticulum chaperone-glucose regulatory protein 78 ( GRP78), calumenin and CX43 were detected by Western blot.</p><p><b>RESULTS</b>(1) Compared with that of the control group, the GRP78 expression level in CVB3 infected group was improved, the expression levels of calumenin and CX43 were all reduced. (2) Compared with that of CVB3 infected group, GRP78 expression level was decreased, and the expression levels of calumenin and CX43 were increased in total flavonoids of astragalus group.</p><p><b>CONCLUSION</b>CVB3 infection may cause endoplasmic reticulum stress of rat myocardium cells by increasing the expression of GRP78 and decreasing the expression of calumenin and CX43. On the other hand, total flavonoids of astragalus can reduce the expression of GRP78 and increase the expression of calumenin and CX43.The results of this experiment may be closely related to the effects of anti-arrhythmia with viral myocarditis caused by CVB3.</p>

The potential effects of endoplasmic reticulum stress on the apoptosis of myocardial cells from mice with heart failure induced by acute viral myocarditis caused by B 3 Coxsackie virus / 中国应用生理学杂志

<p><b>OBJECTIVE</b>To explore the apoptotic pathway mediated by endoplasmic reticulum stress in the mouse myocardium with heart failure induced by acute viral myocarditis caused by B-3 Coxsackie virus.</p><p><b>METHODS</b>Forty BALB/c male mice were randomly divided into 2 groups (n = 20): the control group and the virus infection group. The BALB/c mouse myocarditis was induced by B-3 Coxsackie virus and the mouse behavior was observed conventionally. All the mice were sacrificed on day 7 and the changes of left ventricular pressure (LVP) and the rate of change of left ventricular pressure (LV dp/dt) were measured. The cardiomyocytic apoptosis was analyzed by TUNEL method and the mRNA expression level of endoplasmic reticulum haperones glucose-regulated protein (GRP)78 and GRP94 was detected by RT-PCR.</p><p><b>RESULTS</b>(1) Compared with those of control group, the parameters of cardiac hemodynamics in the virus infection group were significantly decreased (P < 0.01); (2) Compared with that of control group, myocardial apoptosis was significantly increased in the myocardial cells from mice with heart failure induced by acute viral myocarditis (P < 0.01); (3) The mRNA expression level of GRP78 and GRP94 were increased significantly in the virus infection group compared with the control group.</p><p><b>CONCLUSION</b>These findings suggest the endoplasmic reticulum stress may mediate the apoptosis of myocardial cells in the mice myocardium of heart failure induced by acute viral myocarditis caused by B-3 Coxsackie virus.</p>

Myocardial polyamine metabolism and the ischemia-reperfusion injury in the rat heart / 中华心血管病杂志

<p><b>OBJECTIVE</b>To observe the polyamines metabolism changes in rat cardiomyocytes underwent ischemia-reperfusion (I/R) injury.</p><p><b>METHODS</b>A branch of the descending left coronary artery was occluded to induce rat myocardial I/R injury (30 min ischemia followed by 2 h, 6 h, 12 h, and 24 h reperfusion). RT-PCR and Western blot were performed to detect the expression of spermidine/spermine N1-acetyltransferase (SSAT) and ornithine decarboxylase (ODC), the concentrations of polyamines were measured with high performance liquid chromatography in hearts with or without I/R.</p><p><b>RESULTS</b>The myocardial transcription and expression of SSAT and ODC were significantly upregulated. Compared with the sham group, ODC mRNA and SSAT mRNA respectively increased 3.1 fold and 3.8 fold and their proteins respectively increased 3.1 fold and 2.9 fold at 24 h of reperfusion (P < 0.01); the concentrations of spermidine, spermine and the total polyamine pool respectively decreased by 33.6%, 35.3% and 32.9% while putrescine concentration increased by 58.9% at 24 h of reperfusion (P < 0.01).</p><p><b>CONCLUSION</b>Our results suggest that ischemia-reperfusion in the heart may affect polyamine metabolism and the disturbance of polyamine metabolism might thus play a critical role in myocardial I/R injury in this model.</p>

Protective mechanism of the interaction between protein kinase C and calcium sensing receptor in jschemiapreconditioning / 中国地方病学杂志

Objective To investigate the protective mechanism of protein kinase C(PKC)and calcium sensing receptor(CaR)in ischemia preconditioned rat hearts.Methods Using cell culture method,in vitro cultured inhibitor(IPC+CaRI).Apoptosis was detected using TUNEL and Hoechst33342 cell viability was detected by MTT,the protein expression of easpase-12,calpain and CaR in endochylema were detected using Wedtetm blot.ResultsIn I/R group nucleus was shrank,big blue,chromatin concentrated,apoptotle body appeared.Other groups haddifferent fluorescence intensity varying degree,IPC+PKCI+CaRS group had more big blue nucleus.Myocardialcell viability and apoptotic rate,I/R group[(62.99±0.65)%,(19.13±0.87)%],IPC group[(78.67±0.37)%,(14.21±0.74)%],IPC+PKCI group[(71.09±0.52)%,(20.46±0.81)%],IPC+PKCI+CaRS group(66.10±0.75)%,(24.89±1.43)%],IPC+CaRS group[(69.56±0.44)%,(21.64±0.77)%],IPC+CaRI group(85.81±0.60)%,(13.12±0.69)%],all had a difference(P＜0.05 or＜0.01)compared with C group[(100.00)%,(6.02±0. 31)%].Western blot identified that CaR expression in IPC+PKCI and IPC+CaRS,IPC+PKCI+CaRS groupswas more than that in IPC and IPC+CaRI groups;easpase-12 had more active fragment(60×103)in I/R,IPC+CaRS,IPC+PKCI+CaRS groups;ealpain expressions in I/R,IPC,IPC+PKCI,IPC+PKCI+CaRS,IPC+CaRSgroups were higher than those in C and IPC+CaRI,I/R group was the highest one,C group the second,IPC+CaRI the third.Conclusion The interaction of PKC and CaR can reduce the intracellular Ca2+ from sarcoplasmicreticulum thus provide a protection.

The role of calcium-sensing receptor on ischemia/reperfusion-induced rat cardiomyocyte apoptosis / 中华心血管病杂志

<p><b>OBJECTIVE</b>To investigate the role of calcium-sensing receptor (CaR) on ischemia/reperfusion-induced rat cardiomyocyte apoptosis.</p><p><b>METHODS</b>The isolated rat hearts were subjected to 40 min ischemia followed by 2h of reperfusion with or without CaR agonist GdCl3 at the beginning of reperfusion. Control hearts (without ischemia) and ischemic hearts (40 min ischemia without reperfusion) served as controls. The protein expressions of CaR, Bcl-2 and cyt C were detected by Western blot. Cardiomyocyte apoptosis was detected by TUNEL. Mitochondrial potential (Deltaphim) was detected by laser confocal microscopy.</p><p><b>RESULTS</b>Compared to controls groups, the expressions of CaR and apoptotic cells were significantly increased, Deltaphim and expressions of mitochondria cyt C and Bcl-2 were significantly reduced in ischemia/reperfusion hearts with or without GdCl3.</p><p><b>CONCLUSION</b>CaR was involved in the induction of cardiomyocyte apoptosis during ischemia/reperfusion via mitochondrial pathway.</p>

Effect of artemisinin on ischemia/reperfusion injury of isolated rat myocardium / 中国中药杂志

<p><b>OBJECTIVE</b>To observe the effect of artemisinin on the ischemia/reperfusion injury of the iisolated rat myocardium and to preliminarily study the possible mechanism.</p><p><b>METHOD</b>Fifty Wistar rats were randomly divided into 5 groups: a control group, an ischemia/reperfusion (I/R) group, and 3 artemisinin (AS) groups (10, 100, 1000 micromol x L(-1)), 10 rats in each group. Ischemia/reperfusion injury of the isolated rat myocardium was induced by a Langendorff system. The electrocardiogram, the cardiac functional parameters, coronary flow, and the activities of LDH (lactate dehydrogenase), CPK (creatine phosphokinase), SOD (superoxide dis-mutase) and the level of malondiadehyde (MDA) in myocardial tissue, and the myocardial ultrastructures were investigated.</p><p><b>RESULT</b>AS (10,100 micromol x L(-1)) could significantly improve the index of the myocardial function (+/- dp/dt(max), LVSP) after the ischemia/reperfusion, increase the coronary flow, decrease the leakage of LDH and CPK, and increase the SOD activity and decrease the MDA level in cardiac tissues, and alleviate the myocardial ultrastructure injury. But, AS (1000 micromo x L(-1)) did not have the above effects.</p><p><b>CONCLUSION</b>AS (10, 100 micromol x L(-1)) alleviate the myocardial ischemia/reperfusion injury in rats. The mechanism may be related to its functions of antioxidation and scavenging free radicals.</p>

Association between calcium-sensing receptor protein expression and rat cardiomyocyte apoptosis / 中华心血管病杂志

<p><b>OBJECTIVE</b>To investigate the relationship between calcium-sensing receptor protein (CaSR) expression and rat cardiomyocyte apoptosis and related signal transduction pathways.</p><p><b>METHODS</b>The CaSR, BCl2, Caspase3 protein and ERK1/2 phosphorylation or non-phosphorylation were detected by Western blot. Cardiomyocyte apoptosis was detected by flow cytometry and immunofluorescence.</p><p><b>RESULTS</b>CaSR protein was detected in rat cardiac tissue and CaSR activator gadolinium (GdCl3) induced cardiomyocyte apoptosis and increased ERK1/2 phosphorylation and expression of BCl2 and activated Caspase3. The selective mitogen-activated protein kinase (MAPK) inhibitor PD98059 abolished gadolinium -induced ERK1/2 activation and BCl2 expression, further increased the activation of Caspase3 and cardiomyocyte apoptosis.</p><p><b>CONCLUSION</b>Our results demonstrate the CaSR existence in cardiomyocytes and CaSR activation by gadolinium can induce myocyte apoptosis by activating Caspase3 and tyrosine protein kinase pathway.</p>