OBJECTIVETo evaluate the effect of adenosine on endothelin-1 (ET-1) after acute myocardial infarction (AMI) and reperfusion and explore the possible mechanism of no-reflow.

METHODSTwenty-four mini-swine were randomized into three study groups: control group (n=8), adenosine treated group (n=8), and sham-operated group (n=8). The mini-swine in the groups were subjected to 3 hours of coronary occlusion, followed by 60 minutes of reperfusion except those in the sham-operated group. The levels of ET-1 in blood sample, normal, infracted reflow and no-reflow myocardium were evaluated by radioimmuno-assay (RIA). The gene expressions of ET-1 in normal, infracted reflow and no-reflow myocardium were quantified by reverse transcription-polymerase chain reaction.

RESULTSIn both control group and adenosine group, compared with that at the baseline, ET-1 in blood sample significantly increased at 5 minutes and 180 minutes of left anterior descending coronary artery occlusion, as well as 5 and 60 minutes of reperfusion (all P < 0.01). In adenosine group, the levels of ET-1 were significantly lower than those in the control group (P < 0.05, P < 0.01). In both control group and adenosine group, compared with that in normal myocardium, ET-1 levels in both infarcted reflow and no-reflow myocardium significantly increased (both P < 0.01), with the level of ET-1 in no-reflow myocardium significantly higher than that in infarcted reflow myocardium (P < 0.01). In adenosine group, the level of ET-1 in infarcted reflow myocardium was significantly lower than that in the control group (P < 0.01). In both control and adenosine groups, compared with that in normal myocardium, the gene expression of ET-1 in infarcted reflow myocardium was significantly up-regulated (P < 0.01), while that of ET-1 in. no-reflow myocardium significantly down-regulated (P < 0.01). In adenosine group, the level of ET-1 in infarcted reflow myocardium was significantly lower than that in the control group (P < 0.01).

CONCLUSIONThe endothelium injury may be one of the important mechanisms for no-reflow phenomenon. Adenosine cay prevent endothelium from injury to reduce no-reflow.

Adenosine ; pharmacology ; therapeutic use ; Animals ; Disease Models, Animal ; Endothelin-1 ; genetics ; metabolism ; Female ; Male ; Myocardial Infarction ; drug therapy ; physiopathology ; Myocardial Reperfusion ; Swine ; Swine, Miniature

BACKGROUNDHyperglycemia has been shown to be a powerful predictor of poor outcome after ST-segment elevation myocardial infarction (STEMI). This study aimed to evaluate the effect of admission glucose on microvascular flow after successful primary percutaneous coronary intervention (PCI) in patients with STEMI.

METHODSSuccessful primary PCI was performed in 267 patients with STEMI. The maximum ST elevation of single electrocardiogram (ECG) lead before and 60 minutes after PCI was measured, and patients were then divided into 3 groups according to the degree of ST-segment resolution (STR): absent (<30%), partial (30% to 70%) or complete (> or =70%).

RESULTSOf the 267 patients, 48 (18.0%) had absent STR, 137 (51.3%) experienced partial STR, and 82 (30.7%) had complete STR. The degree of STR decreased with increasing admission glucose levels (P=0.032), and patients with hyperglycemia (serum glucose level > or =11 mmol/L) were more likely to have absent STR (P=0.001). Moreover,hyperglycemia was an independent predictor of incomplete STR (odds ratio, 1.870; 95% confidence interval, 1.038 to 3.371, P=0.037).

CONCLUSIONSHyperglycemia on admission is associated with abnormal coronary microvascular reperfusion in patients with STEMI after successful primary PCI, which may contribute, at least in part, to the poor outcomes in these patients.

Adult ; Aged ; Angioplasty, Balloon, Coronary ; methods ; Electrocardiography ; Female ; Glucose ; metabolism ; Humans ; Hyperglycemia ; blood ; pathology ; physiopathology ; Male ; Middle Aged ; Myocardial Infarction ; blood ; physiopathology ; therapy ; Odds Ratio

OBJECTIVE: To determine the improvements of post-infarction heart function after transplantation of autologous skeletal myoblasts transfected with VEGF165 in rabbits. METHODS: Myocardium infarction was induced in rabbits by left anterior descending coronary artery ligation. At 2 weeks, 1.75×10(7) autologous skeletal myoblasts transfected with pcDNA3.1-VEGF165 were infused into the region of MI via direct intramuscular injection; pcDNA3.1 served as a control. RESULTS: The DAPI-labeled and Desmin-positive immunostained skeletal myofibers were found throughout the infracted areas and border zones, and the density of blood capillary in the MI region transplanted by myoblasts with VEGF165 was increased (measured 4 weeks later and compared with controls). Heart function was examined by the Buxco system and demonstrated that maximum dp/dt [(1607.23±102.67) mmHg/s vs (1217.77±89.91) mmHg/s] and minimum dp/dt [(-1535.09 ± 81.34) mmHg/s vs (1174.58 ± 91.5) mmHg/s] were improved in the heart transplanted with the transfected myoblasts(P<0.05). CONCLUSION Autologous skeletal myoblasts transfected with VEGF165 could ameliorate the blood supply in the MI region, and aid recovery of heart function more quickly in post-infarction hearts. This suggests an effective treatment for myocardium infarction.
Animals ; Female ; Myoblasts, Skeletal ; metabolism ; transplantation ; Myocardial Infarction ; physiopathology ; therapy ; Rabbits ; Recovery of Function ; Transfection ; Transplantation, Autologous ; Vascular Endothelial Growth Factor A ; genetics ; metabolism ; Ventricular Function, Left ; physiology

PURPOSE: Ethyl pyruvate has anti-inflammatory properties and protects organs from ischemia/reperfusion (I/R)-induced tissue injury. The aim of this study was to determine whether ethyl pyruvate decreases the inflammatory response after regional I/R injury and whether ethyl pyruvate protects against delayed regional I/R injury in an in vivo rat heart model after a 24 hours reperfusion. MATERIALS AND METHODS: Rats were randomized to receive lactated Ringer's solution or ethyl pyruvate dissolved in Ringer's solution, which was given by intraperitoneal injection 1 hour prior to ischemia. Rats were subjected to 30 min of ischemia followed by reperfusion of the left coronary artery territory. After a 2 hours reperfusion, nuclear factor kappaB, myocardial myeloperoxidase activity, and inflammatory cytokine levels were determined. After the 24 hours reperfusion, the hemodynamic function and myocardial infarct size were evaluated. RESULTS: At 2 hours after I/R injury, ethyl pyruvate attenuated I/R-induced nuclear factor kappaB translocation and reduced myeloperoxidase activity in myocardium. The plasma circulating levels of inflammatory cytokines decreased significantly in the ethyl pyruvate-treated group. At 24 hours after I/R injury, ethyl pyruvate significantly improved cardiac function and reduced infarct size after regional I/R injury. CONCLUSION: Ethyl pyruvate has the ability to inhibit neutrophil activation, inflammatory cytokine release, and nuclear factor kappaB translocation. Ethyl pyruvate is associated with a delayed myocardial protective effect after regional I/R injury in an in vivo rat heart model.
Animals ; Anti-Inflammatory Agents/*pharmacology ; Cell Nucleus/metabolism ; Cytoplasm/metabolism ; Heart/physiopathology ; Inflammation ; Male ; Myocardial Infarction/prevention & control ; Myocardium/*metabolism ; NF-kappa B/metabolism ; Peroxidase/metabolism ; Pyruvates/*pharmacology ; Rats ; Rats, Sprague-Dawley ; Reperfusion Injury/*drug therapy/*metabolism

OBJECTIVETo evaluate the protective effects of 8% emulsified isoflurane after myocardial ischemia-reperfusion injury and its mechanism in rabbits.

METHODSTwenty-four male adult New Zealand white rabbits were anesthetized with intravenous injection of 30 mg/kg pentobarbital followed by 5 mg x kg(-1) x h(-1) infusion. All rabbits were subjected to 30 minutes of left anterior descending coronary artery (LAD) occlusion and 3 hours of subsequent reperfusion. Before LAD occlusion, the rabbits were randomly allocated into three groups for preconditioning treatment (eight for each group). The control group (C group) received intravenously 0.9% NaCl for 30 minutes. The emulsified isoflurane group (EI group) received 8% emulsified isoflurane intravenously till 0.64% end-tidal concentration for 30 minutes that was followed by a 15-minute washout period. The Intralipid group (IN group) received 30% Intralipid for 30 minutes. The infarcted area, plasma malondialdehyde (MDA) content, superoxide dismutase activity (SOD) and nitrite concentration after 3-hour myocardial perfusion were recorded simultaneously.

RESULTSFor the myocardial ischemia-reperfusion injury animals, the infarcted size in the EI group was significantly reduced (91.9% +/- 8%) as compared with control group (39% +/- 6%, t=5.19, P<0.01). The plasma SOD activity and nitrite concentration in EI group were significantly higher than those in control group (t=2.82, t=8.46, P<0.05), but MDA content was lower in EI group than that in control group (t=2.56, P<0.05).

CONCLUSIONSThe results indicate that emulsified isoflurane has a cardioprotection effect against ischemia-reperfusion injury. This beneficial effect of emulsified isoflurane is probably through NO release and consequently by increase in antioxidation of myocardium.

Animals ; Emulsions ; Isoflurane ; administration & dosage ; pharmacology ; Lipid Peroxidation ; drug effects ; Male ; Myocardial Infarction ; drug therapy ; pathology ; Myocardial Reperfusion Injury ; physiopathology ; prevention & control ; Nitric Oxide ; blood ; Rabbits ; Superoxide Dismutase ; metabolism

OBJECTIVETo observe the effects of Panax notoginsenoside (PNS) on tumor necrosis factor-alpha (TNF-alpha) and matrix metalloproteinases-2 (MMP-2) expressions in rats with post-myocardial infarction ventricular remodeling and explore the mechanism.

METHODSRat models of acute infarction ventricular (AMI) were established by ligation of the left anterior descending coronary artery. Twenty-four hours after the operation, the rats were randomized into control and experimental groups for intragastric administration of normal saline (control), fosinopril and PNS at the low, medium and high doses for 4 consecutive weeks. The effects of PNS on the cardiac function index including the left ventricular end-diastolic dimension (LVIDd), left ventricular end-systolic diameter (LVIDs), ejection fraction (EF), percentage of left ventricular systole (FS), mitral early diastolic flow velocity mouth (MV), and heart rate (HR) were observed, and the changes in TNF-alpha and MMP-2 expression were detected after post-myocardial infarction ventricular remodeling.

RESULTSCompared with the control group, PNS at the medium and high doses produced significant improvements in the EF, FS and MV of the rats (P<0.01 or 0.05). TNF-alpha and MMP-2 expressions were significantly decreased by PNS treatment at low, medium and high doses (P<0.01).

CONCLUSIONPNS can inhibit or reduce the expression of TNF-alpha and MMP-2, thereby enhancing left ventricular systolic and diastolic functions, decreasing peripheral resistance, and improving the cardiac function of rats with post-myocardial infarction left ventricular remodeling.

Animals ; Female ; Male ; Matrix Metalloproteinase 2 ; metabolism ; Myocardial Infarction ; drug therapy ; physiopathology ; Panax notoginseng ; chemistry ; Rats ; Rats, Sprague-Dawley ; Saponins ; pharmacology ; therapeutic use ; Tumor Necrosis Factor-alpha ; metabolism ; Ventricular Remodeling ; drug effects

BACKGROUNDExperimental studies and preliminary clinical studies have suggested that growth hormone (GH) treatment may improve cardiovascular parameters in chronic heart failure (CHF). Recombinant human GH (rhGH) has been delivered by a recombinant protein, by plasmid DNA, and by genetically engineered cells with different pharmacokinetic and physiological properties. The present study aimed to examine a new method for delivery of rhGH using genetically modified bioartificial muscles (BAMs), and investigate whether the rhGH delivered by this technique improves left ventricular (LV) function in rats with CHF.

METHODSPrimary skeletal myoblasts were isolated from several Sprague-Dawley (SD) rats, cultured, purified, and retrovirally transduced to synthesize and secrete human rhGH, and tissue-engineered into implantable BAMs. Ligation of the left coronary artery or sham operation was performed. The rats that underwent ligation were randomly assigned to 2 groups: CHF control group (n = 6) and CHF treatment group (n = 6). The CHF control group received non-rhGH-secreting BAM (GFP-BAMs) transplantation, and the CHF treatment group received rhGH-secreting BAM (GH-BAMs) transplantation. Another group of rats served as the sham operation group, which was also randomly assigned to 2 subgroups: sham control group (n = 6) and sham treatment group (n = 6). The sham control group underwent GFP-BAM transplantation, and the sham treatment group underwent GH-BAM transplantation. GH-BAMs and GFP-BAMs were implanted subcutaneously into syngeneic rats with ligation of the left coronary artery or sham operation was performed. Eight weeks after the treatment, echocardiography was performed. hGH, insulin-like growth factor-1 (IGF-1) and TNF-alpha levels in rat serum were measured by radioimmunoassay and ELISA, and then the rats were killed and ventricular samples were subjected to immunohistochemistry.

RESULTSPrimary rat myoblasts were retrovirally transduced to secrete rhGH and tissue-engineered into implantable BAMs containing parallel arrays of postmitotic myofibers. In vitro, they secreted 1 to 2 microg of bioactive rhGH per day. When implanted into syngeneic rat, GH-BAMs secreted and delivered rhGH. Eight weeks after therapy, LV ejection fraction (EF) and fractional shortening (FS) were significantly higher in CHF rats treated with GH-BAMs than in those treated with GFP-BAMs ((65.0 +/- 6.5)% vs (48.1 +/- 6.8)%, P < 0.05), ((41.3 +/- 7.4)% vs (26.5 +/- 7.1)%, P < 0.05). LV end-diastolic dimension (LVEDD) was significantly lower in CHF rats treated with GH-BAM than in CHF rats treated with GFP-BAM (P < 0.05). The levels of serum GH and IGF-1 were increased significantly in both CHF and sham rats treated with GH-BAM. The level of serum TNF-alpha decreased more significantly in the CHF treatment group than in the CHF control group.

CONCLUSIONSrhGH significantly improves LV function and prevents cardiac remodeling in rats with CHF. Genetically modified tissue-engineered bioartificial muscle provides a method delivering recombinant protein for the treatment of heart failure.

Animals ; Bioartificial Organs ; Echocardiography ; Heart Failure ; therapy ; Human Growth Hormone ; administration & dosage ; Myoblasts, Skeletal ; metabolism ; Myocardial Infarction ; pathology ; physiopathology ; therapy ; Rats ; Rats, Sprague-Dawley ; Recombinant Proteins ; administration & dosage ; Tissue Engineering ; Tumor Necrosis Factor-alpha ; blood ; Ventricular Function, Left

OBJECTIVETo explore the effect of adenovirus-mediated human stromal cell-derived factor-1alpha (hSDF-1alpha) on ventricular remodeling in rats with myocardial infarction.

METHODSA recombinant adenoviral plasmid containing hSDF-1alpha cDNA was constructed using homologous recombination in bacteria and the recombinant adenovirus particles expressing hSDF-1alpha (AdV-SDF-1) were prepared. In rat models of myocardial infarction induced by left anterior descending artery occlusion, 1x10(10) PFU AdV-SDF-1 or PFU AdV-LacZ were injected at multiple sites into the infarcted myocardium 1 h after the operation, using 200 l cell-free PBS as the control. Four weeks after the injection, the cardiac function of the rats was analyzed, and the heart tissues were taken after the measurement of hemodynamics. On serial frozen sections, histological observation and morphometric measurement were carried out using a microscopic image analysis system, and the expression of hSDF-1alpha was detected by immunocytochemistry.

RESULTSFour weeks after AdV-SDF-1 injection, the myocardium in the infracted area showed significantly higher expression rates of hSDF-1alpha. The injection resulted in a obvious reduction in the infarct size and collagen content and a marked increase in the left ventricle wall, and the rats showed improved cardiac functions.

CONCLUSIONSDF-1alpha can improve the cardiac structure and function in rats with myocardial infarction by inhibiting collagen synthesis and deposition in the infarcted area.

Adenoviridae ; genetics ; metabolism ; Animals ; Chemokine CXCL12 ; administration & dosage ; biosynthesis ; genetics ; Female ; Gene Transfer Techniques ; Genetic Vectors ; genetics ; Male ; Myocardial Infarction ; physiopathology ; therapy ; Rats ; Rats, Sprague-Dawley ; Recombinant Proteins ; administration & dosage ; biosynthesis ; genetics ; Transfection ; Ventricular Remodeling ; drug effects

The aim of the present study was to investigate the protective effect of polydatin against myocardial ischemia/reperfusion injury in rats and the underlying mechanism. In anesthetized rats, ischemia and reperfusion arrhythmia produced by ligating and loosing the coronary artery was recorded and myocardial infarct size was measured. In Langendorff isolated rat heart, cardiac function was recorded before and after 30 min of global ischemia followed by 60 min of reperfusion. The parameters of cardiac function include left ventricular developed pressure (LVDP), maximal differentials of LVDP (±LVdp/dt(max)) and coronary flow (CF) were measured. Myocardial superoxide dismutase (SOD) activity, the contents of myocardial malondialdehyde (MDA) and nitric oxide (NO) as well as the activity of nitric oxide synthase (NOS) were measured in isolated heart. The results showed: (1) Arrhythmia score and myocardial infarct size were significantly lower in polydatin group than that in the control group (P<0.05, P<0.01); (2) The recovery of LVDP, ±LVdp/dt(max) and CF during reperfusion in polydatin group were significantly better than that in the control rats (P<0.05, P<0.01); (3) SOD activity in polydatin group was significantly higher than that in the control group, but MDA content was lower in polydatin group than that in the control group (P<0.05); (4) NO content and NOS activity, especially constitutive nitric oxide synthase (cNOS) activity in polydatin group were higher than that in the control group (P<0.05); (5) L-NAME, the NOS inhibitor, reversed the protective effect of polydatin against ischemia/reperfusion injury. The results suggest that polydatin has a protective effect against ischemia/reperfusion injury in rat heart. The cardioprotection of polydatin is mainly mediated by cNOS which leading to an increase in NO production.
Animals ; Glucosides ; pharmacology ; Heart ; drug effects ; physiopathology ; Malondialdehyde ; metabolism ; Myocardial Infarction ; pathology ; Myocardial Reperfusion Injury ; drug therapy ; Myocardium ; enzymology ; NG-Nitroarginine Methyl Ester ; pharmacology ; Nitric Oxide ; metabolism ; Nitric Oxide Synthase ; antagonists & inhibitors ; metabolism ; Rats ; Rats, Sprague-Dawley ; Stilbenes ; pharmacology ; Superoxide Dismutase ; metabolism

OBJECTIVETo study the effect of medicines for activating blood and reinforcing Qi on the number of new micro-vessels and the protein expressions of VEGF and bFGF in the infarcted myocardium edge area of acute myocardial infarction (AMI) model in rats.

METHODThe AMI model of rats was established. After the successful model establishment, rats were randomly divided into the sham-operated group, the model group, the Danshen-Huangqi (1 : 2) group, the Danshen-Huangqi (1 : 1) group, the Chuanxiong-Huangqi (1 : 2) group, the Danshen group, the Chuanxiong group, the Chishao group and the Shexiang Baoxin pill group, with five rats in each group. Rats in each medicated group were orally administered with drugs as per 13.5 g x kg(-1) x d(-1) once everyday for three weeks. The immunohistochemical SP method was adopted to detect the expression of vWF in myocardial tissues, and count the number of micro-vessels (MVC). The protein expression of VEGF and bFGF in myocardial tissues were determined by Western blot.

RESULTThe new micro-vessels stained by vWF factor could be found in the infarcted myocardium edge area of the sham-operated group, the model group and all of medicated groups. The sham-operated group show unobvious new micro-vessels in myocardial tissues. A small amount of new micro-vessels could be seen in the infarcted myocardium edge area of the model group. Whereas a larger number of micro-vessels could be seen in the infarcted myocardium edge area of all of medicated groups. The differences between the sham-operated group and the model group had statistical significance (P < 0.05). The differences between each medicated group and the model group had statistical significance as well (P < 0.05 or P < 0.01). The lowest protein expression of VEGF and bFGF was found in myocardium of the sham-operated group, with the statistical significance compared with the model group (P < 0.05). Compared with the model group, each medicated group showed significant increase in the protein expression of VEGF and bFGF, with the statistical significance between them (P < 0.05 or P < 0.01).

CONCLUSIONThe Danshen group, the Chuanxiong group, the Chishao group, the Danshen-Huangqi (1 : 2) group, the Danshen-Huangqi (1 : 1) group and the Chuanxiong-Huangqi (1 : 2) group show the effect in promoting angiogenesis. Their mechanism for promoting angiogenesis may be related to the improvement of the protein expressions of VEGF and bFGF, so as to increase the contents of VEGF and bFGF and promote the angiogenesis of new vessels.

Animals ; Drugs, Chinese Herbal ; administration & dosage ; Fibroblast Growth Factor 2 ; genetics ; metabolism ; Humans ; Male ; Microcirculation ; drug effects ; Microvessels ; drug effects ; physiopathology ; Myocardial Infarction ; drug therapy ; physiopathology ; Neovascularization, Pathologic ; drug therapy ; genetics ; metabolism ; Qi ; Rats ; Rats, Sprague-Dawley ; Vascular Endothelial Growth Factor A ; genetics ; metabolism