OBJECTIVETo investigate the inhibitory effect of tetramethylpyrazine (Tet) preconditioning on overload training-induced myocardial apoptosis in rats, and to explore cardioprotective mechanisms of Tet preconditioning.

METHODSA total of 25 male Sprague-Dawley rats were randomly divided into three groups, including the control group (n=5), the overload training group (overload training for 8 weeks, n=10), and the Tet preconditioning group (Tet preconditioning for 8 weeks before overload training, n=10). After 8 weeks, cardiac structure and myocardial apoptosis were analyzed by histology, transmission electron microscopy, and terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling assay staining. The expressions of Bcl-2, Bax, Caspase-3, and Caspase-9 in myocardium were evaluated by immunohistochemical staining.

RESULTSOverload training caused swelling, disorder, partial rupture, and necrosis of myocardial focal necrotic fibers, as well as mitochondrial vacuolization, cristae rupturing, and blurring. In contrast, Tet preconditioning attenuated the swelling of myocardial fibers, decreased the amount of ruptured fibers, and inhibited mitochondrial vacuolization, resulting in clear cristae. Overload training significantly increased Bax expression and decreased Bcl-2/Bax ratio when compared with the control group (P<0.01). Conversely, Tet preconditioning significantly increased Bcl-2 expression and the Bcl-2/Bax ratio as compared with the overload training group (P<0.05). Overload training dramatically increased the expressions of Caspase-3 and Caspase-9 when compared with the control groupP<0.05). Following Tet preconditioning, the expression of Caspase-3 was significantly reduced compared with the overload training group (P<0.05), while Caspase-9 expression showed a slight decline (P>0.05).

CONCLUSIONTet preconditioning increased the expression of Bcl-2 and reduced the expression of Caspase-3, thereby attenuating overload training-induced myocardial apoptosis, protecting against overload training-induced myocardial injury, and reducing damage to the myocardium due to overload training.

Animals ; Apoptosis ; drug effects ; Caspase 3 ; metabolism ; Caspase 9 ; metabolism ; Immunohistochemistry ; Male ; Myocardium ; enzymology ; pathology ; ultrastructure ; Pyrazines ; pharmacology ; Rats, Sprague-Dawley ; bcl-2-Associated X Protein ; metabolism

OBJECTIVETo assess the effect of Klotho gene transduction on the progression of hypertension and heart damage in spontaneous hypertensive rats (SHRs).

METHODSAn adeno-associated virus (AAV) carrying full-length mouse Klotho cDNA (rAAV.mKL) was constructed for in vivo expression of Klotho. Three different groups of male SHRs and a control group of sex and age-matched Sprague Dawley (SD) rats (5 rats per group) were used. The experimental groups of SHRs received an IV injection of phosphate buffered saline (PBS), rAAV.mKL and rAAV.EGFP, respectively. The control group only received equal-volume of PBS. The whole study has spanned 12 weeks. Plasma levels of insulin-like growth factor-1 (IGF-1) and insulin were measured with ELISA. The weight of whole heart was measured to calculate the heart weight index (HWI). EGFP expression of heart frozen sections was observed by fluorescence microscopy. Expression of mRNA and protein of Klotho, IGF-1, IGF-1 receptor (IGF-1R) and p-Akt were determined with RT-PCR, immunohistochemical analysis, and Western blotting. Hypertrophic myocardial cell and collagen fiber were observed by histological examination following Haematoxylin-Eosin and Masson staining.

RESULTSTransduction of rAAV.mKL can significantly prevent the increase of blood pressure in SHRs. Compared with the control group, the levels of Klotho mRNA and protein have both increased, and the plasma levels of IGF-1, insulin and glucose were elevated, whereas the expression of phosphor-Akt (also called Protein Kinase B, PKB) was decreased in the rAAV.mKL group. Furthermore, a decrease of hypertrophic myocardial cells and collagen fibers was noticed in the rAAV.mKL group compared with the control group.

CONCLUSIONThe Klotho gene can attenuate the progression of hypertension and abolishes myocardial hypertrophy and myocardial fibrosis. The protective effect observed in the rAAV.mKL group of SHRs may be attributed to increased Klotho protein and suppression of insulin and IGF-1 signaling pathways through inhibition of Akt phosphorylation.

Animals ; Blood Glucose ; Blood Pressure ; genetics ; Gene Expression ; Glucuronidase ; genetics ; metabolism ; Hypertension ; genetics ; metabolism ; pathology ; Insulin ; blood ; Insulin-Like Growth Factor I ; genetics ; metabolism ; Male ; Myocardium ; metabolism ; pathology ; ultrastructure ; Proto-Oncogene Proteins c-akt ; metabolism ; RNA, Messenger ; genetics ; metabolism ; Rats ; Rats, Inbred SHR ; Transduction, Genetic

OBJECTIVETo investigate the effect of hydrogen sulfide-induced delayed preconditioning on glutathione S-transferase (GST) expression during myocardial ischemia-reperfusion in rats.

METHODSSprague-Dawley male rats were randomly divided into 4 groups (n= 10 in each): Group S (sham operation group), Group IR (ischemia/reperfusion group), Group H (IR+ NaHS 0.05 mg/kg iv, 24 h before ischemia) and Groups D receiving IR+NaHS 24 h before ischemia and 5-hydroxydecanoate (5-HD)15 min before ischemia. Animals in groups IR, H and D were subjected to ischemia by 30 min of coronary artery occlusion followed by 2 h of reperfusion. At the end of the reperfusion, myocardial infarct size (IS) was examined. Glutathione S-transferase (GST) was measured by Western blotting. The myocardial ultrastructures were observed under the electron microscopy.

RESULTSThe IS was significantly smaller in Group H than that in Group IR [(25.40 ± 3.54)% compared with (38.27 ± 5.64)%, P<0.05]. The GST expression in myocardium was significantly higher in Group H than that in Group IR. Microscopic examination showed less myocardial damage in Group H than in Group IR. The protective effects of delayed preconditioning by hydrogen sulfide was prevented by 5-HD pre-treatment.

CONCLUSIONThe hydrogen sulfide-induced delayed preconditioning attenuates myocardial IR injury possibly through up-regulating glutathione S-transferase expression in rats.

Animals ; Disease Models, Animal ; Glutathione Transferase ; metabolism ; Hydrogen Sulfide ; administration & dosage ; therapeutic use ; Ischemic Preconditioning, Myocardial ; Male ; Myocardial Reperfusion Injury ; enzymology ; pathology ; therapy ; Myocardium ; enzymology ; ultrastructure ; Rats ; Rats, Sprague-Dawley

OBJECTIVETo investigate whether the administration of the ultra-filtration extract from Danggui Buxue Decoction (EDBD) was able to protect cardiomyocytes from oxidative injury of rats induced by hydrogen peroxide (H(2)O(2)) and its potential mechanism.

METHODSMyocardial cells from 1- to 2-day-old neonatal rats were cultured in Dulbecco's modified Eagle's medium low-glucose and Ham's F12 medium (1:1), and the cellular injury was induced by H(2)O(2). The ultra-filtration extract mixture from Angelica sinensis and Hedysarum polybotrys was given in three doses of 3.75, 7.5, and 15 mg/mL. Morphological changes of cardiomyocytes were observed by microscope. Survival rate of myocardial cells was assessed using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The cardiomyocyte damages were estimated by detecting lactate dehydrogenase (LDH) and creatine kinase (CK) releases in the medium, superoxide dismutase (SOD) activities, and intracellular malondialdehyde (MDA) and myeloperoxidase (MPO) contents. The levels of caspase-3 and heat shock protein 70 (hsp70) mRNA expression in cardiomyocytes were measured by reverse transcription polymerase chain reaction.

RESULTSThe EDBD could protect the cardiomyocytes from H(2)O(2) injury in a dosedependent manner (3.75, 7.50, and 15.00 mg/mL). The EDBD could significantly decrease LDH and CK leakages and intracellular MDA and MPO contents, increase SOD activity, up-regulate hsp70 expression, and down-regulate caspase-3 expression.

CONCLUSIONThe EDBD has protection on cardiomyocytes injured by H(2)O(2) through improving cell antioxidant ability, up-regulating hsp70 expression, and inhibiting caspase-3 activity.

Animals ; Animals, Newborn ; Caspase 3 ; genetics ; metabolism ; Cell Survival ; drug effects ; Creatine Kinase ; metabolism ; Cytoprotection ; drug effects ; Drugs, Chinese Herbal ; pharmacology ; Gene Expression Regulation ; drug effects ; HSP70 Heat-Shock Proteins ; genetics ; metabolism ; L-Lactate Dehydrogenase ; metabolism ; Malondialdehyde ; metabolism ; Mice ; Myocardium ; pathology ; ultrastructure ; Myocytes, Cardiac ; drug effects ; enzymology ; pathology ; Oxidative Stress ; drug effects ; Peroxidase ; metabolism ; Phytotherapy ; Plant Extracts ; pharmacology ; RNA, Messenger ; genetics ; metabolism ; Rats ; Reverse Transcriptase Polymerase Chain Reaction ; Superoxide Dismutase ; metabolism ; Ultrafiltration

OBJECTIVETo explore the synergistic protection of Danhong Injection (丹红注射液, DHI) and ischemic postconditioning on myocardial reperfusion injury in minipigs.

METHODSAcute myocardial infarction model was made by balloon occlusion in left anterior descending coronary artery (LAD) of minipigs, and then postconditioning was simulated through inflation/deflation of the angioplasty balloon. Minipigs were divided into four groups: the sham operation group (SH group), the ischemia/reperfusion group (I/R group), the ischemic postconditioning group (POC group) and DHI combined with ischemic postconditioning group (PAD group, DHI 20 mL through ear vein), six in each group. After 24-h continuous observation, myocardial infarction size was assessed by triphenyltetrazolium staining (TTC). Morphological changes of ischemic myocardium were observed by light microscopy, and cardiomyocyte ultrastructure was studied with electron microscopy. The superoxide dismutase (SOD) and malondialdehyde (MDA) activity in heart homogenates were measured by a biochemical method.

RESULTSThe myocardial infarction size was smaller in the POC group than in the I/R group (0.26 ± 0.02 vs. 0.37 ± 0.09, P<0.05), and the PAD group (0.14 ± 0.08) displayed a significantly reduced infarction size relative to the I/R group (P<0.01) and POC group (P<0.05). The damage of myocardial tissue was severe in the I/R group shown by light and electron microscopy: myocardial fibers disorder, sarcoplasmic dissolution, myofilament fracture, mitochondria swelling and even vacuolization formation and a large number of inflammatory cell infiltrations. Compared with the I/R group, reduction of reperfusion injury in the PAD group included more orderly arranged myocardial fibers, less infiltration of inflammatory cells and maintenance of mitochondrial integrity. Compared with the I/R group, the damage of myocardial tissue in the POC group was improved, but not as significant as that in the PAD group. SOD levels in the POC group and the PAD group were significantly higher than those in the I/R group (96.96 ± 13.43, 112.25 ± 22.75 vs. 76.32 ± 10.63, P<0.05), and MDA was significantly lower in the POC group and the PAD group compared to the I/R group (1.27 ± 0.19, 1.09 ± 0.21 vs. 1.47 ± 0.16, P<0.05).

CONCLUSIONDHI and ischemic postconditioning show a synergistic cardioprotection on myocardial reperfusion injury in minipigs.

Animals ; Coronary Angiography ; Drugs, Chinese Herbal ; administration & dosage ; therapeutic use ; Injections ; Ischemic Postconditioning ; Malondialdehyde ; metabolism ; Myocardial Infarction ; complications ; pathology ; Myocardial Reperfusion Injury ; complications ; drug therapy ; prevention & control ; Myocardium ; enzymology ; pathology ; ultrastructure ; Superoxide Dismutase ; metabolism ; Swine ; Swine, Miniature

OBJECTIVE: To investigate the effect of isoflurane delayed preconditioning on the activation of caspase-3 and the expression of Bcl-2 in rabbit myocardium during ischemia reperfusion and the possible mechanism. METHODS: Forty New Zealand male white rabbits were randomly divided into 4 groups: a sham group (Group C), an I/R group, an isoflurane group (Group S), and an isoflurane + opioid recepters inhibitor group (Group N). Group S was exposed to 2.0% isoflurane for 2 h. Group N was given naloxone (6.0 mg/kg) before exposing to 2.0% isoflurane. Group C and Group I/R were exposed for 2 h to 100% oxygen, serving as untreated controls. Twenty-four hours later, Group S and Group N underwent 40 min of coronary occlusion followed by 2 h of reperfusion. At the end of the reperfusion, infarct size(IS) and area at risk(AAR) were defined by Evans and TTC staining. The myocardial ultrastructure was observed by electron microscopy. The levels of the myocardial Bcl-2 and caspase-3 expression were determined by Western blot. RESULTS: The caspase-3 activity of Group S was significantly lower than that of Group I/R(P<0.05). The IS was significantly reduced in Group S(19.7%+/-2.8%) as compared with Group I/R(37.8%+/-1.7%) (P<0.05). Microscopic examination showed less myocardial damage in Group S than in Group I/R. CONCLUSION Isoflurane delayed preconditioning can inhibit the apoptosis of myocardium by up-regulating the expression of Bcl-2 and down-regulating the activation of caspase-3, which may be part of the molecular mechanism of isoflurane delayed preconditioning on myocardial preservation.
Animals ; Apoptosis ; drug effects ; Caspase 3 ; metabolism ; Gene Expression Regulation ; drug effects ; Ischemic Preconditioning, Myocardial ; methods ; Isoflurane ; pharmacology ; therapeutic use ; Male ; Myocardial Ischemia ; drug therapy ; pathology ; Myocardial Reperfusion Injury ; prevention & control ; Myocardium ; metabolism ; ultrastructure ; Proto-Oncogene Proteins c-bcl-2 ; metabolism ; Rabbits ; Random Allocation

OBJECTIVETo study the effects of different doses of taurine (Tau) on calcium ion concentration ([Ca2+]i) and ATPase on cardiocyte membrane of diastole heart failure rats.

METHODDiastole heart failure model was established by the coarctation of abdominal aorta. Four weeks after operation, forty diastole heart failure rats were divided into four groups randomly as follows, model (normal saline 2 mL), taurine (400 mg x kg(-1) x d(-1)), taurine (200 mg x kg(-1) x d(-1)), taurine (100 mgx kg(-1) x d(-1)), with 10 rats for each group (n=10), and 10 sham operation rats was taken as control(normal saline, 2 mL). After 4 weeks administration, Isolate single cardiocyte by enzymatic isolation method which were loaded with Ca2+-sensitive fluorescent indicator Fluo-3/AM. [Ca2+]i was measured by laser scanning confocal microscope [LSCM], and represented it by fluorescent intensity [FI]; ATPase activity of cell membrane was measured by the method of enzymatic reaction chromatometry.

RESULTCompared with the control group, [Ca2+]i in cardiocyte increased markedly and the ATPase activity of cardiocyte membrane decreased significantly in the model group. Compared with the model group, fluorescent value decreased and ATPase activity increased significantly in Tau high-dose group; fluorescence value and ATPase activity decreased significantly in Tau mid-dose group; fluorescent value decreased and ATPase activity increased significantly in Tau low-dose group.

CONCLUSIONLarge dosage of Tau can increase ATPase activity on cardiocyte membrane, improve [Ca2+]i in cardiocyte and antagonise calcium overload of DHF rats.

Adenosine Triphosphatases ; metabolism ; Animals ; Calcium ; metabolism ; Diastole ; drug effects ; Disease Models, Animal ; Female ; Heart Failure ; drug therapy ; metabolism ; Male ; Myocardium ; pathology ; ultrastructure ; Myocytes, Cardiac ; drug effects ; metabolism ; pathology ; Rats ; Rats, Wistar ; Taurine ; administration & dosage ; pharmacology ; therapeutic use

OBJECTIVETo observe the effect of heart protection on diabetic cardiomyopathy in rats by tripterysium glucosides.

METHODThe rat diabetic cardiomyopathy rats model are made by streptozotocin, then divided into tripterysium glucosides group (n=8) and model group (n=8). In addition, the control group is established (n=8). Glucosides group was orally administrated tripterysium glucosides (18 mg x kg(-1)), the control groups was orally administrated same volume NS for 3 months. Blood sugar, heart function and cardiac index were detected after 3 months. Immunohistochemical techniques were used to detect NF-kappaB and ICAM-1 expression. Ultrastructure of cardiac muscle cell were observed by electronmicroscope.

RESULTCompared with model group, cardiac index was decreased after tripterysium glucosides administration, and LVSP, LVEDP, + dp/dtmax, -dp/dtmax, were improved, and the expression of nuclear Factor-kappaB (NF-kappaB) and intercellular adhension molecule-1 (ICAM-1) was inhibited. Ultrastructure of cardiac muscle cell such as mitochondrion and cardiac muscle fibers was atttenuated.

CONCLUSIONTripterysium glucosides could protect rat diabetic cardiomyopathy rats heart. These function may be related to inflammatory reaction inhibition and immunosuppression of tripterysium glucosides.

Animals ; Blood Glucose ; metabolism ; Cardiomyopathies ; etiology ; metabolism ; pathology ; physiopathology ; Diabetes Mellitus, Experimental ; complications ; Gene Expression Regulation ; drug effects ; Glucosides ; administration & dosage ; pharmacology ; therapeutic use ; Heart ; drug effects ; Intercellular Adhesion Molecule-1 ; metabolism ; Male ; Myocardium ; ultrastructure ; NF-kappa B ; metabolism ; Rats

OBJECTIVETo investigate the protective effects of preconditioning morphine on rabbit myocardium during ischemia-reperfusion.

METHODSThirty New Zealand male white rabbits were randomly assigned to three groups: control, I/R and morphine groups. In morphine group 1.0 mg/kg morphine was given preoperationaly, in control and I/R groups 1.0 ml/kg NS was given. Twenty-four hours later rabbits in morphine and I/R groups underwent 40 min of coronary occlusion followed by 2 hours of reperfusion; for control group only sham operation was performed. At the end of the reperfusion, infarct size (IS) and area at risk (AAR) were defined by Evans blue and TTC staining. At the end of the reperfusion blood samples were taken for determination of plasma SOD activity and MDA levels. The heart was harvested and levels of the HSP27 were determined by Western blot, and the heart ultrastructures were observed under the electron microscopy.

RESULTSCompared with I/R group,morphine significantly reduced infarct size (21.5%+/-2.4% Compared with 37.8%+/-1.7%, P<0.05). The morphine had a lower level of MDA and higher levels of SOD and HSP27 than those in I/R.

CONCLUSIONPreconditioning of morphine demonstrates cardioprotective effect on ischemia/reperfusion injury, which may be associated with increased HSP27 levels in the heart.

Animals ; HSP27 Heat-Shock Proteins ; metabolism ; Ischemic Preconditioning, Myocardial ; methods ; Male ; Malondialdehyde ; metabolism ; Morphine ; pharmacology ; Myocardial Reperfusion Injury ; pathology ; prevention & control ; Myocardium ; metabolism ; ultrastructure ; Rabbits ; Random Allocation ; Superoxide Dismutase ; metabolism

Confocal laser scanning microscopy(CLSM) is a new technique for microscopic imaging, which can collect the transverse section image of the samples and produce three-dimensional reconstruction and present higher spatial resolution than the conventional light microscope. As a precision instrument for the microscopic image, it plays an important role in forensic pathology. The article reviews the recent research achievements from sudden cardiac death, bullet wound and nervous system damage, etc, and explores the potential applications of the forensic pathology research and forensic practice.
Calcium/metabolism* ; Craniocerebral Trauma/pathology* ; Death, Sudden, Cardiac/pathology* ; Forensic Pathology/methods* ; Humans ; Image Processing, Computer-Assisted ; Microscopy, Confocal ; Myocardium/ultrastructure* ; Sensitivity and Specificity ; Trauma, Nervous System/pathology* ; Wounds and Injuries/pathology* ; Wounds, Gunshot/pathology*