Rong Shuan Jiao Nang in the treatment of acute mountain sickness and high altitude myocardial ischemic syndrome in Yushu

To evaluate the therapeutic effects of Rong Shuan Jiao Nang （RSJN） on treatment of acute mountain sickness （AMS） and high altitude myocardial ischemic syndrome in workers in Yushu, three groups were studied： group A （60 patients with AMS, given RSJN）, group B （15 patients with altitude myocardial ischemic syndrome, given RSJN）, and group C （control, without drugs）. All studied subjects were lowland workers who were first time entry to Yushu for work at an altitude of 4 250 m. During the course of treatment, a routing physical examina- tion was performed, AMS Lake Louise Scores were estimated, arterial oxygen saturation （SaO2）, electrocardiography and hemoglobin concentration were measured before and after using RSJN for 10 days. In group A, the effective rate was 68 %, symptomatic improvement in 54 cases （90 %） within 5 days. In group B, the effective rate was 93 %, episodes of angina pectoris stopped in 12 patients within 3 - 7 days, one lasted 8 days. After treatment, the level of SaO2 increased 15.5 %, 21.8 % and 5.6 % in group A, group B and group C, respectively. RSJN tak- en at the start of the arrival at Yushu can decrease AMS scores and facilitate cure. If taken after the illness has begun, RSJN may help lessen symptoms, especially effectively improved angina pectoris of the high altitude myocardial ischemic syndrome. Symptoms usually subside after 3 - 8 days. RSJN should be continually used lbr at least 7 days after ascent.

Changes of cTnI in myocardial ischemic and reperfusion injury during correction of cardiac defects in children

Objective The purpose of this study is to investgate changes of cTnI in myocardial ischemic and reperfusion injury during correction of cardiac defects in children. Methods From June, 1999 to May,2000,45 children (30 male, 15 female) undergoing correction of cardiac defects were divided into three groups randomly: group Ⅰ no myocardial ischemia,group Ⅱ myocardial ischemia less than 60 minutes, group Ⅲmyocardial ischemia 】 60 minutes. There were no significant differences in the three groups in age, sex ratio, C/T ratio, or left ventricular function. Blood samples for analysis were collected before skin incision and at time intervals up to 6 days postoperatively. Analysis of creatine kinase MB.LDH and cardiac-specific troponin I was used for the detection of myocardial damage. Meantime, the ECG was checked for myocardial infarction. After the reperfusion, myocardial tissue was obtained from the free wall of right ventricle myocardial structure studies. Results The level of cTnI was increased

Role of β-Adrenergic Signal Transduction Pathway on Myocardial Ischemic Preconditioning of Rats

To study the changes in every part of the β-adrenergic signal transduction pathway and their effects on ischemic preconditioning of rat myocardium in vivo. SD rats were divided into three groups： IP group, I/R group and CON group. The IP group was further divided into PC1-, 2-, 3-, and PC1＋, 2＋, 3＋ groups according to preconditioning procedure. The rats received surgical procedure and underwent left coronary artery occlusion and reperfusion. We analyzed the infarct size by TTC staining, measured serum myocardial enzymes, studied the β-AR Bmax and Kd by radioligand binding assay of receptors, checked the activity of AC and PKA by the method of biochemistry and examined the content of cAMP by radioimmunoassay. The infarct area was much smaller in the IP group than in the I/R group （P〈0. 001）, while the enzymes were significantly higher in I/R （P〈0. 001）. The Bmax of β-AR in IP was much higher than that in I/R （P〈0. 001）, but no difference in Kd could be seen between IP and I/R groups. In IP, the activity of AC and PKA and the content of cAMP were higher than those in I/R （P〈0.05, 0. 002 and 0. 001, respectively）. In the procedure of preconditioning, the content of cAMP and the activity of PKA showed the characteristic of cyclic fluctuation. Ischemic preconditioning can protect the heart from necrosis and reduce endo-enzyme leakage. The system of β-adrenergic signal transduction pathway probably takes part in the protection effect of the IP, which might be elicited by the PKA .

Therapeutic application of chick early amniotic fluid: effective rescue of acute myocardial ischemic injury by intravenous administration

Myocardial regeneration has been considered a promising option for the treatment of adult myocardial injuries.Previously,a chick early amniotic fluid(ceAF)preparation was shown to contain growth-related factors that pro-moted embryonic growth and cellular proliferation,though the nature of the components within ceAF were not fully defined.Here we tested whether this ceAF preparation is similarly effective in the promotion of myocardial regen-eration,which could provide an alternative therapeutic for intervening myocardial injury.In this study,a myocardial ischemic injury model was established in adult mice and pigs by multiple research entities,and we were able to show that ceAF can efficiently rescue damaged cardiac tissues and markedly improve cardiac function in both experimental models through intravenous administration.ceAF administration increased cell proliferation and improved angio-genesis,likely via down-regulation of Hippo-YAP signaling.Our data suggest that ceAF administration can effectively rescue ischemic heart injury,providing the key functional information for the further development of ceAF for use in attenuating myocardial injury.

EFFECTS OF GLIBENCLAMIDE, GLIMEPIRIDE, AND GLICLAZIDE ON ISCHEMIC PRECONDITIONING IN RAT HEART

Objective To compare the influence of different sulfonylureas on the myocardial protection effect of ischemic preconditioning (IPC) in isolated rat hearts, and ATP-sensitive potassium channel current (IKATP) of rat ventricular myocytes. Methods Isolated Langendorff perfused rat hearts were randomly assigned to five groups: (1) control group, (2) IPC group, (3) IPC+glibenclamide (GLB, 10 μmol/L) group, (4) IPC+glimepiride (GLM, 10 μmol/L) group, (5) IPC+gliclazide (GLC, 50 μmol/L) group. IPC was defined as 3 cycles of 5-minute zero-flow global ischemia followed by 5-minute reperfusion. The haemodynamic parameters and the infarct size of each isolated heart were recorded. And the sarcolemmal IKATP of dissociated ventricular myocytes reperfused with 10 μmol/L GLB, 1 μmol/L GLM, and 1 μmol/L GLC was recorded with single-pipette whole-cell voltage clamp under simulated ischemic condition. Results The infarct sizes of rat hearts in IPC (23.7%±1.3%), IPC+GLM (24.6%±1.0%), and IPC+GLC (33.1%±1.3%) groups were all significantly smaller than that in control group (43.3%±1.8%; P<0.01, n=6). The infarct size of rat hearts in IPC+GLB group (40.4%±1.4%) was significantly larger than that in IPC group (P<0.01, n=6). Under simulated ischemic condition, GLB (10 μmol/L) decreased IKATP from 20.65±7.80 to 9.09±0.10 pA/pF (P<0.01, n=6), GLM (1 μmol/L) did not significantly inhibit IKATP (n=6), and GLC (1 μmol/L) decreased IKATP from 16.73±0.97 to 11.18±3.56 pA/pF(P<0.05, n=6). Conclusions GLM has less effect on myocardial protection of IPC than GLB and GLC. Blockage of sarcolemmal ATP-sensitive potassium channels in myocardium might play an important role in diminishing IPC-induced protection of GLM, GLB, and GLC.

Remote ischemia conditioning-an endogenous cardioprotective strategy from outside the heart

Objective A general review was made of studies involving： （1） The experimental evidence of remote ischemic preconditioning （RIPC） and relative clinical studies, （2） The experimental and clinical evidences of remote ischemic postconditioning （RIPOC）, （3） The potential mechanistic pathways underlying their protective effects.Data sources The data used in this review were mainly from manuscripts listed in PubMed that were published in English from 1986 to 2010. The search terms were ＂myocardial ischemia reperfusion injury＂, ＂ischemia preconditioning＂,＂ischemia postconditioning＂, ＂remote preconditioning＂ and ＂remote postconditioning＂.Study selection （1） Clinical and experimental evidence that both RIPC and RIPOC produce preservation of ischemia reperfusion injury （IRI） of myocardium and other organs, （2） Studies related to the potential mechanisms, by which remote ischemic conditioning protects myocardium against IRI.Results Both RIPC and RIOPC have been shown to attenuate myocardial IRI in laboratory animals. Also, their cardioprotective effects have appeared in some clinical studies. Except the external, the detailed internal mechanisms of remote ischemic conditioning have been generally described. Through these descriptions better protocols can be developed to provide improved cardioprotective procedures.Conclusions Remote ischemic conditioning is an endogenous cardioprotective mechanism from outside the heart that protects against myocardial IRI and represents a general form of inter-organ protection. Remote ischemic conditioning may have an immense impact on clinical practice in the near future.

Protective effects of hypovolemic hypotension preconditioning on cardiopulmonary function after myocardium ischemia/reperfusion injury

Objective: To identify the protective effects of hypovolemic hypotension preconditioning on cardiopulmonary function after myocardial ischemia/reperfusion injury and to explore the possible mechanism.Methods: Twenty-four male white rabbits were randomly assigned to two groups. In the control group, ischemia/reperfusion animals(Group I/R, n=10) were subjected to thirty-minute occlusion of left anterior descending coronary artery and two-hour reperfusion. Animals in hypovolemic hypotension preconditioning group (Group HHP, n=14) experienced brief systemic ischemia preconditioning through blood withdrawl to lower blood pressure to 40%-50% of the baseline before myocardial ischemia/reperfusion. Hemodynamic parameters were recorded. Blood sample was taken to measure superoxide dismutase (SOD), malondialdehyde (MDA) and nitrogen monoxide (NO) changes with blood gas analysis. Myocardium specimens were sampled to examine apoptosis-related gene interleukin-1 beta converting enzyme (ICE) mRNA. Results: Cardiac mechanical function and lung gas exchange remained stable in Group HHP with a significant increase in NO level; while in Group I/R without preconditioning, cardiopulmonary dysfunction was present after 2 h reperfusion associated with a significant reduction in NO formation and an increase in MDA (P<(0.001)). There was negative expression of ICE mRNA in the two groups.Conclusions: Hypovolemic hypotension preconditioning significantly improves cardiopulmonary function and increases NO formation and the protective benefit associated with hypovolemic hypotension preconditioning of the heart may be regulated through NO mediated mechanism.