OBJECTIVETo study the effects of modified Mahuang Fuzi Xixin Decoction extract (MFXDE) on ischemia/reperfusion induced atrioventricular (A-V) block in rabbits model.

METHODSNew Zealand rabbits were randomly divided into six groups, three test groups (Group TA, TB, TC) and three control groups (Group CA, CB, CC), 10 in each. MFXDE 2 mL/kg was given twice a day by gastrogavage to the test groups, while to the control groups, equal volume of normal saline was given instead, for 3 successive days. Twenty minutes after the last gastrogavage, right coronary artery ligation was performed in rabbits under anesthesia with 1.2 g/kg of 20% urethane via ear marginal vein injection, and lasted for 15 min (Group TA and CA), 60 min (Group TB and CB), and 120 min (Group TC and CC), respectively. ECG lead-II and His Bundle ECG were recorded at different time points to observe P-R interval and A-H interval.

RESULTSP-R interval and A-H interval in the test groups were shorter than in the control groups significantly (all P < 0.05) at the time point of 5 min after ischemia; and at the reperfusion stage, a re-extending phenomenon of P-R and A-H could be found in the CC group after 60 min reperfusion (P < 0.05), but it didn't occure in all the other test groups.

CONCLUSIONMFXDE could improve the ischemia/reperfusion induced A-V conductive function.

Animals ; Atrioventricular Block ; drug therapy ; etiology ; physiopathology ; Disease Models, Animal ; Drugs, Chinese Herbal ; administration & dosage ; Female ; Humans ; Male ; Myocardial Reperfusion Injury ; complications ; Rabbits ; Random Allocation

Brief ischemic episodes that induce myocardial and coronary endothelial dysfunction may alter the responses to inotropic drugs. To determine the effects of inotropic drugs in stunned myocardium, the coronary blood flow (CBF), myocardial oxygen consumption (MVO2), and regional mechanical function in response to intracoronary dobutamine, epinephrine, amrinone, and calcium chloride (CaCl2) were measured before (normal) and 30 min after a 15-min-period occlusion of the left anterior descending artery (stunned) in an open-chest canine model. Percent segment shortening (%SS) and post-systolic shortening (%PSS) were determined. Myocardial extraction of oxygen (EO2) and lactate (E(lac)) was calculated. The inotropic drugs increased %SS, CBF, and MVO2 in normal myocardium. Epinephrine and amrinone decreased, while dobutamine and CaCl2 did not affect EO2. The ischemia and reperfusion itself significantly reduced %SS and E(lac), and increased %PSS. In stunned myocardium, the responses to inotropic drugs were not significantly altered, except that they progressively reduced %PSS and epinephrine did not affect EO2. These findings indicate that a brief episode of ischemia does not affect the mechanical and metabolic coronary flow responses to inotropic drugs, although it abolishes direct vasodilator responses to epinephrine.
Amrinone/administration and dosage ; Animals ; Calcium Chloride/administration and dosage ; Cardiotonic Agents/*administration and dosage ; Comparative Study ; Dobutamine/administration and dosage ; Dogs ; Dose-Response Relationship, Drug ; Epinephrine/administration and dosage ; Female ; Male ; Myocardial Contraction/*drug effects ; Myocardial Stunning/*drug therapy/etiology/*physiopathology ; Oxidation-Reduction/drug effects ; Oxygen Consumption/*drug effects ; Reperfusion Injury/complications/*drug therapy/*physiopathology ; Treatment Outcome

To study the therapeutic effect and possible mechanism of icariin on myocardial ischemia-reperfusion injury ( MIRI) model in diabetes rats. The model of diabetic rats were induced by Streptozotocin (STZ), then the model of MIRI was established by ligating the reversible left anterior descending coronary artery for 30 min, and then reperfusing for 120 min. totally 40 male SD were randomly divided into five groups: the control group (NS), the ischemia reperfusion group (NIR), the diabetes control group (MS), the diabetic ischemia reperfusion group (MIR) and the diabetic ischemia reperfusion with icariin group (MIRI). The changes in blood glucose, body weight and living status were observed; the enzyme activity of serum CK-MB, LDH, GSH-Px and myocardium SOD and the content MDA and NO in myocardium were detected; the myocardial pathological changes were observed by HE staining; the myocardial Caspase-3, the Bcl-2, Bax protein expressions were detected by Western blot. The result showed that the diabetes model was successfully replicated; myocardial ischemia-reperfusion injury was more serious in diabetes rats; icariin can increase NO, SOD, GSH-Px, Bcl-2 protein expression, decrease MDA formation, CK-MB and LDH activities and Caspase-3 and Bcl-2 protein expressions and myocardial damage. The result suggested that icariin may play a protective role against ischemia reperfusion myocardial injury in diabetes rats by resisting oxidative stress and inhibiting cell apoptosis.
Animals ; Apoptosis ; drug effects ; Caspase 3 ; metabolism ; Creatine Kinase ; metabolism ; Diabetes Mellitus, Type 2 ; complications ; Drugs, Chinese Herbal ; administration & dosage ; Flavonoids ; administration & dosage ; Humans ; Ischemia ; drug therapy ; etiology ; physiopathology ; Male ; Malondialdehyde ; metabolism ; Myocardial Reperfusion Injury ; drug therapy ; etiology ; metabolism ; physiopathology ; Myocardium ; metabolism ; Proto-Oncogene Proteins c-bcl-2 ; metabolism ; Rats ; Rats, Sprague-Dawley ; Superoxide Dismutase ; metabolism ; bcl-2-Associated X Protein ; metabolism

OBJECTIVETo observe the development of arrhythmia induced by ischemia/reperfusion (I/R) of the right coronary artery in rabbits and the intervening effect of Chinese medicine Qiangxin Fumai Granule (QFG), a Chinese preparation for activating yang and promoting blood circulation, on it.

METHODSRabbit right coronary artery I/R model was adopted. Forty healthy adult rabbits were randomly divided into 5 groups, the sham-operation group, the model group, the atropine group, the high-dose QFG group, and the low-dose QFG group, eight in each group. The drugs were administered via duodenal perfusion 10 min after ischemia. The changes of AA interval before and after medication were observed and the scores of arrhythmia were calculated.

RESULTSDuring ischemia period, AA interval prolonged for more than 40 ms in the model group, and the scores of arrhythmia showed a rising trend along with the prolonging of ischemia, with the presence of atrial-ventricular block (AVB) and aggravating of sinus and atrial arrhythmia; during reperfusion period, the incidence of AVB decreased, and AA interval somewhat decreased. The AA intervals and scores of arrhythmia in the high and low-dose QFG groups were significantly lower than those in the model group respectively (P < 0.01 or P < 0.05).

CONCLUSIONQFG is beneficial for shortening AA interval and preventing arrhythmia induced by I/R.

Animals ; Anti-Arrhythmia Agents ; administration & dosage ; pharmacology ; therapeutic use ; Arrhythmias, Cardiac ; drug therapy ; physiopathology ; Coronary Artery Disease ; complications ; Dose-Response Relationship, Drug ; Drugs, Chinese Herbal ; administration & dosage ; pharmacology ; therapeutic use ; Female ; Male ; Myocardial Ischemia ; complications ; Myocardial Reperfusion Injury ; etiology ; physiopathology ; Phytotherapy ; Rabbits ; Random Allocation ; Treatment Outcome

OBJECTIVETo observe the protective effect of compound acanthopanax senticosus injection (CASI) on myocardial ischemia-reperfusion arrhythmia in rats.

METHODThe myocardial ischemia-reperfusion model was induced by 30 min coronary occulusion and 60 min reperfusion in openchest anesthetized rats. The changes of arrhythmia with electrocardiogram lead II, the activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px), the contents of malondialdehyde (MDA) and Ca2+ in myocardium were determined.

RESULTIn rats treated by CASI (in a dosage of 25, 50 and 100 mg x kg(-1) femoral vein infusion at 30 min after coronary occulusion), the incidence of myocardial ischemia-reperfusion ventricular arrhythmias, for instance the ventricular tachycardia (VT) and ventricular fibrillation (Vf), was effectively prevented, the appearing time of arrhythmia was delayed and the duration of arrhythmia was shortened, while the elevated ST segment lowered as well. At the same time, the contents of myocardial Ca2+ and MDA were decreased significantly as well as the activities of myocardial SOD and GSH-Px increased markedly.

CONCLUSIONCASI is of protective effect on myocardial ischemia-reperfusion arrhythmia, which may be related to scavenging the oxygen free radicals and Ca2+ overload formed during reperfusion.

Animals ; Anti-Arrhythmia Agents ; isolation & purification ; pharmacology ; Arrhythmias, Cardiac ; drug therapy ; etiology ; physiopathology ; Calcium ; metabolism ; Drug Combinations ; Drugs, Chinese Herbal ; isolation & purification ; pharmacology ; Electrocardiography ; Eleutherococcus ; chemistry ; Female ; Ginsenosides ; isolation & purification ; pharmacology ; Glutathione Peroxidase ; metabolism ; Male ; Malondialdehyde ; metabolism ; Myocardial Reperfusion Injury ; complications ; Myocardium ; metabolism ; pathology ; Panax ; chemistry ; Phytotherapy ; Plants, Medicinal ; chemistry ; Rats ; Rats, Wistar ; Saponins ; isolation & purification ; pharmacology ; Superoxide Dismutase ; metabolism