Humans ; Ischemia ; metabolism ; pathology ; therapy ; Ischemic Postconditioning ; methods ; Myocardial Reperfusion Injury ; metabolism ; pathology ; therapy

AIMTo study the varies and effects of ischemic preconditioning of myocardium on every part of adrenergic receptor-adenyl cyclase system in rats in vivo.

METHODSSD rats were randomly divided into three groups: CON group (n = 6), IP group (n = 12) and I/R group (n = 12). Surgical procedure included intermittent left coronary artery occlusion and reperfusion. After the procedure, the hearts were extracted. We analyzed the infarct size by TTC staining, measured serum myocardial enzymes, studied the beta-AR Bmax and KD by radioligand binding assay of receptors (RAB), and checked the activity of AC and the content of cAMP by radioimmunoassay (RIA).

RESULTSInfarct area were much smaller in IP group than in I/R group (P < 0.05). CK, CK-MB, LDH were significantly higher in I/R group (P < 0.01). The Bmax of beta-AR in IP group were much higher than in I/R group (P < 0.01). No difference of KD could be seen between IP and I/R group. In IP group, the activity of AC and the content of cAMP were higher than I/R group (P < 0.05).

CONCLUSIONIschemic preconditioning can protect the heart from necrosis and reduce endo-enzyme leakage. Ischemic preconditioning can increase the density of beta-AR, the activity of AC and the content of cAMP, which shows that the system of adrenergic receptor-adenyl cyclase system probably takes part in the protection of IP.

Adenylyl Cyclases ; metabolism ; Animals ; Female ; Ischemic Preconditioning, Myocardial ; Myocardial Ischemia ; metabolism ; pathology ; Rats ; Rats, Sprague-Dawley ; Receptors, Adrenergic, beta ; metabolism

Sudden cardiac death(SCD) from early myocardial ischemia is often lack of typically morphological findings and clinical manifestation, thus cases of SCD may be suspected as criminal cases. It is necessary to clarify the cause of death, which is significance for medico-legal investigation. This article reviewed the latest advancement in the studies on the application of inorganic ions, CK-MB, cTn, ANP and BNP for certification of death from SCD in order to provide a practical way for diagnosis of SCD in forensic pathology.
Atrial Natriuretic Factor/metabolism* ; Autopsy ; Biomarkers/metabolism* ; Calcium/metabolism* ; Cause of Death ; Creatine Kinase, MB Form/metabolism* ; Death, Sudden, Cardiac/pathology* ; Forensic Pathology ; Humans ; Myocardial Infarction/pathology* ; Myocardial Ischemia/pathology* ; Myocardium/pathology* ; Natriuretic Peptide, Brain/metabolism* ; Troponin/metabolism*

OBJECTIVE: To investigate the signification of CTnI in acute myocardial infarction. METHODS: The model of myocardial infarction was established by ligating the left ventricle branch. Immunohistochemistry and image analysis were used to detect the change of CTnI in the model, and The sensitivity of immunohistochemistry and HE coloration were also compared. RESULTS: The acute myocardial infarction tissue showed obvious depletion of CTnI, there was no characterization of myocardial infarction in HE coloration. CONCLUSION CTnI is sensitive to diagnosis of acute myocardial infarction.
Animals ; Antibodies, Monoclonal ; Disease Models, Animal ; Female ; Immunohistochemistry ; Male ; Myocardial Infarction/metabolism* ; Myocardial Ischemia/pathology* ; Myocardium/pathology* ; Rabbits ; Sensitivity and Specificity ; Time Factors ; Troponin I/metabolism*

OBJECTIVETo investigate the expression profile of interleuki-1β (IL-1β) in rat myocardium at different time points during hypoxia/reoxygenation(H/R)transition.

METHODSThe isolated Langendorff perfused rat heart model was established.Forty SD rats were randomly divided into sham group (A group) and hypoxia/reoxygenation group (H/R group). The H/R group rats were subdivided into H/R 0.5 h group(B group), H/R 1 h group(C group), H/R 2 h group(D group)according to reoxygenation time. The left ventricular development pressure(LVDP), maximal rates of increase/decrease of the left ventricular pressure(±dp/dtmax) were continuously recorded. The concentration of interleukin-1β(IL-lβ) and creatine kinase-MB (CK-MB) in myocardium was measured by ELISA. The mRNA expression of IL-lβ in myocardium was determined by RT-PCR. Microstructure of myocardium was observed under light microscopy.

RESULTSThe value of LVDP and ±dp/dtmax in hypoxia/reoxygenation group rat were significantly lower than that in sham group(P < 0.05). The expression of IL-lβ and CK-MB at protein level and the expression of IL-1β at mRNA level in hypoxia /reoxygenation group were higher than that in sham group(P < 0. 05). There were significant differences of the above parameters among H/R 0.5 h, 1 h, 2 h group(P <0.05). The concentration of IL-1β and CK-MB, the mRNA expression of IL-1β were higher in H/R 2 h group than that of other groups(P < 0.05).

CONCLUSIONThe high expression of IL-Iβ in myocardium after myocardial hypoxia /reoxygenation in rats might lead to. ischemia/reperfusion injury.

Animals ; Creatine Kinase, MB Form ; metabolism ; Disease Models, Animal ; Hypoxia ; metabolism ; pathology ; Interleukin-1beta ; metabolism ; Myocardial Ischemia ; metabolism ; Myocardium ; metabolism ; pathology ; Rats ; Rats, Sprague-Dawley

OBJECTIVE: To study the correlation between quantity of the connexin43 express and ischemia time in rabbit. METHODS: Left coronary arteries were ligated to create early myocardial ischemia during distinct time, HBFP staining was used in the ischemia spot and SP method was used to show the expression of connexin43 and the ischemia are were measured by the computer image analysis. RESULTS: Negative correlation was observed between the connexin43 quantity and the ischemia time. The significant was difference. CONCLUSION With ischemia time raised, expression of connexin43 was descented.
Animals ; Connexin 43/metabolism* ; Female ; Immunohistochemistry ; Male ; Myocardial Ischemia/pathology* ; Myocardium/pathology* ; Rabbits ; Staining and Labeling/methods* ; Time Factors

OBJECTIVE: To estimate the significance of myocardial collagen I in the early acute myocardial ischemia of human. METHODS: The myocardial paraffin block had normal group, early myocardial ischemia group and myocardial infarction group. The myocardial collagen I was observed with immunohistochemical staining and analyzed by half-quantity. RESULTS: The similar expression of collagen I was observed in the cytoplasm and nucleolus in two groups. CONCLUSION The collagen I appeared in the myocardium of early acute myocardial ischemia of human. It may be an important index for postmortem diagnosis of the early acute myocardial ischemia.
Collagen Type I/metabolism* ; Death, Sudden, Cardiac ; Forensic Pathology ; Humans ; Myocardial Ischemia/metabolism* ; Postmortem Changes ; Time Factors

Brain Ischemia ; metabolism ; pathology ; prevention & control ; Humans ; Ischemic Preconditioning ; methods ; Myocardial Reperfusion Injury ; metabolism ; pathology ; prevention & control ; Reperfusion Injury ; metabolism ; pathology ; prevention & control

OBJECTIVETo explore the cardioprotection effect of co-treatment with ischemic postconditioning and preconditioning in ischemia/reperfusion (I/R) injury and the related mechanism.

METHODSMale Sprague-Dawley rats were used for Langendorff isolated heart perfusion. The hearts were subjected to global ischemia for 60 min followed by 120 min of reperfusion. The cardiomyocyte viability was measured by MTT-formazan method, and the cardiac injury was evaluated by the levels of lactate dehydrogenase (LDH) in the coronary effluent. Ventricular hemodynamic parameters were also measured.

RESULTIn 60 min of ischemia and 120 min of reperfusion group, ischemic postconditioning increased formazan content, reduced LDH release, but hemodynamic parameters did not improved. Co-treatment with ischemic postconditioning and preconditioning during the prolonged ischemia further improved the hemodynamic parameters. The calcium activated potassium channel antagonist paxilline attenuated the effect of co-treatment with ischemic postconditioning and preconditioning.

CONCLUSIONIschemic postconditioning and preconditioning may synergically protect myocardium from severe ischemia injury, which may be related to calcium-activated potassium channel.

Animals ; Cell Survival ; In Vitro Techniques ; Ischemic Preconditioning, Myocardial ; methods ; L-Lactate Dehydrogenase ; metabolism ; Male ; Myocardial Ischemia ; pathology ; physiopathology ; Myocardial Reperfusion Injury ; metabolism ; physiopathology ; prevention & control ; Myocardium ; metabolism ; pathology ; Potassium Channels, Calcium-Activated ; metabolism ; Rats ; Rats, Sprague-Dawley

Animals ; Apoptosis ; Bradykinin ; metabolism ; Bradykinin Receptor Antagonists ; Ischemia ; metabolism ; Ischemic Preconditioning ; Muscle, Skeletal ; blood supply ; metabolism ; pathology ; Myocardial Infarction ; metabolism ; Myocardium ; pathology ; Swine ; Swine, Miniature