Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0022116 (ischemia)
 91,303 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Regional left ventricular contractility caused by myocardial stunning as a result of transient ischemia and postreperfusion injury is a reversible state it can however persist even for several month. It seems reasonable to shorten this period as much as possible. The aim of the study was to estimate the influence of treatment with metoprolol or enalapril on the recovery of contractile function of left ventricle in patients after acute myocardial infarction treated thrombolytically. Investigations were carried out in 127 patients (mean age 62.3 +/- 11.9 years). Metoprolol was used in 37 patients in dose 0.02-0.05 g b.i.d., enalapril in 48 patients 0.0025-0.01 g b.i.d. 42 patients were not treated with any beta-blocker or ACE inhibitor. In all patients echocardiographic study was performed 3 times: on 2-3rd day following acute myocardial infarction immediately before introducing the treatment with metoprolol or enalapril, after 1 month and after 3 months. Echocardiographic study wall motion index (WMI) was calculated basing on. Significant decrease in WMI was observed after 1 month compared to its value on 2-3rd day acute myocardial infarction and after 3 months compared to 1 month after myocardial infarction in each of 3 subgroups of patients. No statistically significant differences in WMI were found out between studied subgroups. Neither metoprolol nor enalapril started on 2-3rd after thrombolytic treatment of acute myocardial infarction do not affect the recovery of contractile function of stunned myocardium.
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PMID:[Influence of treatment with metoprolol or enalapril on recovery of contractile function of the left ventricle in patients after acute myocardial infarction treated by thrombolytics]. 1052 15

Hospital mortality from acute myocardial infarction has decreased in the last two decades. Left ventricular dysfunction therefore have been mainly due to ischemia. After extensive myocardial infarction, there are processes of adaptation (remodeling) which result in altered geometry of the left ventricle. The effects of this on neurohormonal systems (organ regulation), on the changed ratio of myocyte mass and collagen content owing to reactive and reparative fibrosis (organ texture) and on the molecular and cellular mechanisms (organ structure) are of crucial importance. Depending on the structural changes, the myocardial contractility decreases. This is associated with an activation of the circulating renin-angiotensin-aldosterone system (RAAS). The fundamental knowledge available has led to the therapeutic use of ACE inhibitors in the post-infarct period. This treatment enabled a sustained reduction of mortality in several large-scale randomized studies. The effect of early administration in patients with clinical signs of heart failure and/or left ventricular dysfunction was very much greater compared to unselected controls. Only 17 and 13 patients had to be treated after selection in order to save one life in the AIRE and TREACE Study respectively (NNT: number needed to treat), whereas e.g. in the ISIS-4 study 200 unselected patients had to be treated. In clinical practice, however, this life-saving therapy is only used in every second patient requiring treatment. With consideration of an individual form of treatment (anterior infarction, large infarct area, reinfarction, clinical signs of heart failure as well as arterial hypertension and diabetes mellitus), a greater acceptance of evidence-based guidelines is thus desirable. Treatment with a high dose may be expected to be of additional benefit.
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PMID:[Left ventricular remodeling: pathophysiological mechanisms and therapeutic recommendations]. 1065 89

Primary diastolic failure is typically seen in patients with hypertensive or valvular heart disease as well as in hypertrophic or restrictive cardiomyopathy but can also occur in a variety of clinical disorders, especially tachycardia and ischemia. Diastolic dysfunction has a particularly high prevalence in elderly patients and is generally associated, with low mortality but high morbidity. The pathophysiology of diastolic dysfunction includes delayed relaxation, impaired LV filling and/or increased stiffness. These conditions result typically in an upward displacement of the diastolic pressure-volume relationship with increased end-diastolic, left atrial and pulmo-capillary wedge pressure leading to symptoms of pulmonary congestion. Diagnosis of diastolic heart failure requires three conditions: (1) presence of signs or symptoms of heart failure; (2) presence of normal or slightly reduced LV ejection fraction (EF > 50%) and (3) presence of increased diastolic filling pressure. Assessment of diastolic function can be performed with several non-invasive (2D- and Doppler-echocardiography, color Doppler M-mode, Doppler tissue imaging, MR-myocardial tagging, radionuclide ventriculography) and invasive techniques (micromanometry, angiography, conductance method). Doppler-echocardiography is the most useful tool to routinely measure diastolic function. Different techniques can be used alone or in combination to assess LV diastolic function, but most of them are dependent on heart rate, pre- and afterload. The transmitral flow pattern remains the starting point, since it is easy to acquire and rapidly categorizes patients into normal (E > A), delayed relaxation (E < A), and restrictive (E >> A) filling patterns. Invasive assessment of diastolic function allows determination of the time constant of relaxation from the exponential pressure decay during isovolumic relaxation, and the evaluation of the passive elastic properties from the slope of the diastolic pressure-volume (= constant of chamber stiffness) and stress-strain relationship (= constant of myocardial stiffness). The prognosis of diastolic heart failure is usually better than for systolic dysfunction. Diastolic heart failure is associated with a lower annual mortality rate of approximately 8% as compared to annual mortality of 19% in heart failure with systolic dysfunction, however, morbidity rate can be substantial. Thus, diastolic heart failure is an important clinical disorder mainly seen in the elderly patients with hypertensive heart disease. Early recognition and appropriate therapy of diastolic dysfunction is advisable to prevent further progression to diastolic heart failure and death. There is no specific therapy to improve LV diastolic function directly. Medical therapy of diastolic dysfunction is often empirical and lacks clear-cut pathophysiologic concepts. Nevertheless, there is growing evidence that calcium channel blockers, beta-blockers, ACE-inhibitors and AT2-blockers as well as nitric oxide donors can be beneficial. Treatment of the underlying disease is currently the most important therapeutic approach.
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PMID:Diastolic heart failure. 1072 7

It is of primary importance for the clinical cardiologist to keep in mind the parameters allowing an adequate prognostic stratification in post-infarct patients in view of making the best diagnostic and therapeutic choices. A diagnostic strategy, based on a pathophysiologic approach, should evaluate four aspects: spontaneous and stress-induced ischemia, myocardial viability, and ventricular arrhythmias. Spontaneous ischemia has an undefined prognostic value, especially in the thrombolytic era; therefore it seems reasonable to perform invasive procedures in patients who are not stabilized by an adequate medical therapy or with large jeopardized areas. In asymptomatic patients, a provocative stress test allows a more articulated decisional iter. It is preferably to perform the test by the most physiological exercise EKG, together with the echocardiographic imaging, after the acute phase. It has a high negative predictive value, but a low positive predictive value. The detection of myocardial viability is frequently performed, mainly in patients with large post-ischemic myocardial dysfunction. Among all the proposed methods, the echo-dobutamine test mainly allows to estimate patients in whom revascularization may result in more benefit. The role of ventricular arrhythmias as an independent prognostic factor is debated and has to be always considered in relationship to other parameters, particularly left ventricular function. Regarding the therapeutic strategy, the indications from recent trials, related to antithrombotic drugs, beta-blockers, ACE-inhibitors, nitrates, Ca-blockers and antiarrhythmic drugs, are emphasized.
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PMID:[Diagnostic and therapeutic strategies in post-infarct]. 1082 80

The clinical relevance of diastolic dysfunction in heart failure has recently been emphasized. In fact, the presence of signs of heart failure does not imply a depressed left ventricular systolic function; moreover, the severity of heart failure and effort tolerance are more closely related to diastolic than to systolic indexes. However, the principal trials about the treatment of heart failure were mainly addressed to patients with significant left ventricular systolic dysfunction, whereas the optimal therapy for diastolic dysfunction is not well known. The aim of this review was to assess the rationale and the therapeutic options in heart failure due to diastolic dysfunction. A diastolic dysfunction can be exclusive or associated with systolic dysfunction, as in dilated cardiomyopathy. It has to be noted that in this disease an improvement of diastolic function was demonstrated for most of the drugs currently employed in the treatment of heart failure, such as vasodilators, ACE inhibitors, beta-blockers, digitalis, and other inotropic drugs. Moreover, the favorable effect of the treatment on diastolic parameters (reduction of left ventricular filling pressure, regression of restrictive filling pattern) is associated with a positive prognostic impact. The main objective of the treatment of heart failure with preserved left ventricular systolic function is to control the symptoms by means of lowering high left ventricular filling pressure without significantly lowering cardiac output. According to the therapeutic guidelines of the American College of Cardiology/American Heart Association Task Force, the drugs indicated to treat symptomatic patients with heart failure and preserved left ventricular systolic function are diuretics and nitrates. Potentially useful, but with insufficiently proven efficacy are beta-blockers, calcium antagonists and ACE inhibitors, whereas direct vasodilators and inotropic drugs were considered inadvisable. It is important to remember that the treatment might possibly be oriented to the cause and also to the possible precipitating factors of the heart failure syndrome (i.e. ischemia, tachycardia, arrhythmias, hypertension). In conclusion, considering the relatively common incidence of heart failure due to prevalent diastolic dysfunction, and the few available data about the therapeutic options in these patients, large multicenter trials devoted to the treatment of this syndrome are needed.
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PMID:[Heart failure due to diastolic dysfunction: the treatment principles]. 1083 33

Renin-angiotensin system (RAS) is involved in the regulation of superoxide dismutase (SOD) and nitric oxide (NO) equilibrium, and its modulation protects hearts from ischemic dysfunction. We examined the effect of a new antisense-oligodeoxynucleotides (AS-ODNs) directed at ACE mRNA on SOD and iNOS expression during myocardial ischemia. Sprague-Dawley rats were treated with saline, AS-ODNs, or inverted-ODNs (IN-ODNs), given with liposome DOTAP/DOPE. Hearts were excised and subjected to 25 min of ischemia followed by 30 min of reperfusion. Ischemia-reperfusion in saline-treated hearts resulted in a decrease in the expression of SOD and an increase in the expression of inducible NOS (iNOS) genes concurrently with myocardial dysfunction. AS-ODNs, but not IN-ODNs, protected hearts against functional deterioration, and upregulated SOD expression and inhibited the expression of iNOS. ACE protein expression was decreased in the rat hearts of the AS-ODNs-treated group, but not in the IN-ODNs group. Thus manipulation of RAS with AS-ODNs directed at ACE mRNA can ameliorate cardiac dysfunction and modulate expression of SOD and iNOS at genomic level.
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PMID:Modulation of myocardial SOD and iNOS during ischemia-reperfusion by antisense directed at ACE mRNA. 1111 1

Allograft coronary endothelial cells can serve as potent stimulators (antigen-presenting cells) as well as targets of allogeneic lymphocyte reactivity. Independent of the cause leading to endothelial cell injury after transplantation, endothelial cell activation and dysfunction occurs, associated with modification in endothelial cell-dependent molecule expression. The prevalence of coronary endothelial vasomotor dysfunction is approximately 20-30% during the first year, and 30-40% in the long-term follow-up. Importantly, no association is detectable between endothelial dysfunction and intimal thickness, suggesting two distinct entities of allograft vasculopathy. Early predictors of vasomotor dysfunction are proinflammatory cytokines and endothelin expression. Repetitive subendocardial ischemia during myocardial stress (due to microvascular dysfunction) may result in an impairment of left ventricular function. In non-transplant patients coronary endothelial dysfunction predicts cardiac events during long-term follow-up. It is reasonable that early administration of endothelial-protective compounds is necessary for protection of allograft endothelial dysfunction and vasculopathy during follow-up. The explanted donor heart may offer a potential for gene therapy techniques including modification of allograft phenotype and modulation of the host alloimmune response. Other protective strategies may include improvement of cardioplegic solutions and reperfusion strategies, recovery of the imbalance between vasoactive mediators, and treatment with HMG-CoA-reductase inhibitors and/or ACE inhibitors.
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PMID:Heart allograft endothelial cell dysfunction. Cause, course, and consequences. 1115 95

There have been many studies concerning the hemodynamics and physiological mechanisms in ischemic heart disease, little is known about molecular mechanisms during myocardial ischemia in in vivo study. As the signal transduction pathway responsible for myocardial hypertrophy and apoptosis, janus kinase (JAK) and signal transducers and activators of transcription (STAT) are suggested to play an important role. However, whether in vivo activation of JAK-STAT pathway occurs during myocardial ischemia is still unknown. The purpose of this study was to determine whether myocardial JAK or STAT is activated in ischemic heart, and to evaluate the angiotensin blockade on the pathway. Myocardial infarction was produced by ligation of the coronary artery in Wistar rats. After myocardial ischemia, we analysed both activated levels and total amounts of JAK1, JAK2, STAT1 and STAT3 by Western blot analyses at 0, 5, 15, 30, 60, 120 and 240 min. Compared with JAK activities at 0 min, JAK1 activities were significantly increased at 60 and 120 min (3.0- and 3.7-fold, respectively, P<0.01). JAK2 and STAT1 activities of ischemic myocardium were unchanged through the time course. STAT3 activities were increased at 5 min (3.3-fold, P<0.01) and markedly enhanced at 30, 60 and 120 min (4.6-, 7.7- and 8.7-fold, respectively, P<0.01). Pretreatment with imidapril (ACE inhibitor) and candesartan cilexitil (AT1 receptor antagonist) significantly prevented the increase in the phosphorylation of JAK1 at 120 min and STAT3 at 30 and 120 min. Sis-inducing factor (SIF) DNA complex was supershifted by specific anti-STAT3 antibody, indicating that increased SIF complex at least contained activated STAT3 proteins in ischemic myocardium. Imidapril and candesartan cilexitil inhibited the activation of SIF DNA binding at 1 day after coronary ligation. In conclusion, we showed that JAK1 and STAT3 were activated by ischemia from the basal activities in in vivo rat myocardial ischemia model. Imidapril and candesartan cilexitil prevented the increase in phosphorylated JAK1 and STAT3, thereby suggesting that angiotensin II, especially angiotensin II type I receptor, partially mediates activation of myocardial JAK-STAT pathway in acute myocardial ischemia.
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PMID:Myocardial ischemia activates the JAK-STAT pathway through angiotensin II signaling in in vivo myocardium of rats. 1116 35

Inhibition of the renin-angiotensin system (RAS) has been shown to be beneficial in providing cardioprotective effects in humans, but the mechanism of these effects is not well understood. In this study, we examined the effects and mechanism of RAS inhibitors on ischemia/reperfusion (IR)-induced myocardial injury in rats. Rats were randomly divided into five groups and treated with vehicle (C), angiotensin converting enzyme inhibitor (ACE-I), angiotensin II type 1 receptor antagonist (AT1-A), angiotensin II type 2 receptor antagonist (AT2-A) or ACE-I plus bradykinin B2 antagonist. Ten minutes after administration, the left main coronary artery was ligated for 45 min, and then reperfused for 120 min. IR-induced cardiomyocyte apoptosis was assessed by terminal deoxyribonucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) assay and confirmed by typical DNA laddering. Mitogen-activated protein kinase, extracellular signal-regulated protein kinase (ERK) and c-Jun NH2-terminal protein kinase (JNK) activity in the ischemic zone were measured by an in vitro kinase assay. The duration of ventricular tachycardia (VT) during ischemia was reduced by AT2-A and ACE-I, and increased by AT1-A and ACE-I+icatibant. ACE-I and AT2-A reduced apoptosis (by 54% and 53%) and infarct size (by 42% and 41%), while AT1-A increased apoptosis (by 86%) and infarct size (by 45%). These changes were negatively correlated with the change in ERK activity. The effects of ACE-I on apoptosis and infarct size were abolished by the coadministration of icatibant. Apoptosis was correlated with the occurrence of VT (r=0.837, p<0.001). These results suggest that both the accumulation of bradykinin and inhibition of AT2 receptor are cardioprotective against IR injury through the activation of ERK, but not JNK.
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PMID:Mechanism of the cardioprotective effect of inhibition of the renin-angiotensin system on ischemia/reperfusion-induced myocardial injury. 1132 78

The increase of radical forms of mitochondrial respiratory chain compounds (MRCC) is an indicator of an increased risk of the formation of oxygen radicals. Using electron paramagnetic resonance (EPR), we found an increase of signals corresponding to ubisemichinone radical (.QH) and ironsulfur proteins radical forms (-FeS) of these respiratory chain compounds during ischemia in the isolated perfused rat heart (.QH increased from 1.51 to 3.08, .FeS1 from 1.14 to 2.65 arbitrary units). During the 5-min reperfusion, the signals returned to normoxic levels. In isolated mitochondria exposed to anoxia and reoxygenation the radical forms of .QH and FeS2 changed in a similar manner as in the intact heart. A combination of in vivo captopril treatment and in vitro L-arginine administration significantly decreased the levels of MRCC radicals in the isolated myocardium (.QH from 2.61 to 1.72 and .FeS, from 1.82 to 0.46 under normoxia; .QH from 4.35 to 2.66 and .FeS1 from 1.93 to 1.35 during ischemia). This decrease in MRCC radical forms was associated with increased NO levels in the perfusate, determined as NO2- / NO3-, as well as tissue NO levels determined using EPR as the dinitrosyl iron complex (DNIC). These results provide new information about the cardioprotective effects of ACE inhibitors and L-arginine.
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PMID:The effect of captopril on nitric oxide formation and on generation of radical forms of mitochondrial respiratory chain compounds in ischemic rat heart. 1170 52


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