Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0151744 (myocardial ischemia)
 31,282 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The effect of the nucleoside Inosie-F (inosin) on the intracardiac hemodynamics and the contraction and relaxation of a diseased myocardium was studied in the clinic and in experiments. An examination was made of 102 patients with macrofocal myocardial infarction (22 received inosin by intravenous drip in a single dose of 200 mg in the acute stage of infarction; 60 patients were given inosin pills in a daily dose of 800 mg in the restoration period for one month, and 20 patients were given placebo). Comparative appraisal of treatment in the period of rehabilitation showed prevailing improvement in the condition of individuals treated with inosin, positive ECG dynamics, increase of cardiac output and decrease of peripheral resistance. In experiments on 28 dogs with a model of acute myocardial ischemia a noticeable improvement in myocardial contraction and relaxation in the absence of negative ECG dynamics was recorded after intravenous infusion of inosin. Inosin achieves maximum effect by 60-90 mins after the beginning of infusion.
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PMID:[Indications for the use of inosine in myocardial infarct (a clinical and experimental study)]. 34 35

The applicability of the adenosine triphosphate (ATP) catabolites, inosine and hypoxanthine as markers of myocardial ischemia in humans with coronary artery disease has been investigated. Inosine and hypoxanthine were assayed enzymatically after separation by a new column chromatographic method. The myocardial lactate extraction at rest (17 +/- 13%) changed to production values (-23 +/- 28%) during pacing-induced angina (P less than 0.0005). Coronary venous inosine values increased from 535 +/- 185 nmol/l at rest to 1030 +/- 740 nmol/l during angina (P less than 0.005), the arterial values amounted to 770 +/- 325 nmol/l and 805 +/- 515 nmol/l respectively (P, NS). The calculated myocardial uptake of inosine at rest (27 +/- 16%) changed to production values (-25 +/- 29%) during angina (P less than 0.0005). Coronary venous hypoxanthine increased from 1000 +/- 760 nmol/l at rest to 1235 +/- 800 nmol/l during angina (P, NS), the arterial values amounted to 1300 +/- 1040 nmol/l and 1235 +/- 800 nmol/l respectively (P, NS). The myocardial extraction changed from 20 +/- 18% at rest to -5.4 +/- 29% during angina (P less than 0.0025). The significant positive correlation (r = 0.61, P less than 0.0025) between myocardial release and uptake of inosine and lactate during severe angina demonstrates that anaerobic glycolysis is accompanied by ATP breakdown. During a second pacing period at less increased pressure--rate product after nitroglycerin, lactate production (-1.7 +/- 22%) already occurred whereas extraction of inosine (19 +/- 19%) and hypoxanthine (24 +/- 15%) did not change. In conclusion, lactate functions as a sensitive marker of myocardial ischemia and inosine is useful in detecting ischemic myocardial energy deficiency by the indication of insufficient glycolytic ATP supply.
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PMID:Myocardial release of inosine, hypoxanthine and lactate during pacing-induced angina in humans with coronary artery disease. 42 23

The morphological analysis of the portions of the interventricular septum and left ventricular wall in cats has revealed dystrophic and necrotic changes in the myocardium after administration of caffeine followed by adrenaline: haemorrhages, intravascular thrombogenesis, dystrophic and necrobiotic changes in myocytes. In early periods of acute ischemic heart disease morphine, fibrinolysin, heparin and Inosie F either abolished (fibrinolysin) or considerably decreased (heparin and Inosie F) a tendency toward intravascular thrombogenesis and damage to the myocardial parenchyma.
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PMID:[Effect of agents used in the therapy of acute ischemic heart disease on the histomorphological changes in the myocardium in acute dystrophy]. 47 57

During ischemia, myocardial adenosine triphosphate is degraded to adenosine, inosine and hypoxanthine. These nucleosides are released into coronary venous blood and may provide an index of ischemia; adenosine may also participate in the autoregulation of coronary flow. In dogs, the temporal relations between reactive hyperemic flow and nucleoside concentrations in regional venous blood were correlated after brief occlusions of a segmental coronary artery. Reactive hyperemia and adenosine release peaked together in 10 seconds, persisted for 10 to 30 seconds and then decreased in a pattern consistent with the hypothesis that they are related. During initial reflow after 45 seconds of ischemia, mean concentrations of adenosine, inosine and hypoxanthine increased, respectively, to 52, 67 and 114 nmol/100 ml plasma; after 5 minutes of ischemia, the respective levels increased to 58, 1,570 and 1,134 nmol and fell quickly. In nine patients there was a similar release of nucleosides into coronary sinus blood during reperfusion after 59 to 80 minutes of ischemic arrest during cardiac surgery. With initial reflow, adenosine, inosine and hypoxanthine levels reached 65, 655 and 917 nmol/100 ml of blood, respectively. Inosine and hypoxanthine concentrations remained high for 5 to 10 minutes after cardiac beating resumed, often when production of lactate had decreased. The results indicate that postischemic release of nucleosides reaches significant levels in man as well as animals, is parallel with the duration of ischemia, is temporary and may be a useful supplement to measurement of lactate as an index of prior myocardial ischemia.
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PMID:Release of nucleosides from canine and human hearts as an index of prior ischemia. 75 70

The purpose of this study was to determine the changes in cardiac interstitial fluid (ISF) purine metabolites during 90 min of regional myocardial ischemia. To collect ISF metabolites and measure local coronary blood flow (CBF), cardiac microdialysis probes were implanted into the left anterior descending artery (LAD) and left circumflex artery (LC) perfused myocardium of chloralose-urethane anesthetized dogs (n = 7). Regional ventricular wall thickness was measured in the LAD and LC perfused regions with sonomicrometric crystals, using systolic wall thickening (SWT) as an index of regional ventricular function. Regional myocardial ischemia, produced by occlusion of the LAD, resulted in a decrease in CBF (hydrogen clearance) from 77.3 +/- 12.4 to 10.9 +/- 4.4 ml/min/100 g (P less than 0.05), and systolic wall thinning (control SWT = 15.5 +/- 2.2%; ischemic SWT = -6.8 +/- 1.7%). ISF adenosine was transiently elevated in the ischemic region, obtaining a maximum sixfold increase after 15 min of ischemia. Inosine, hypoxanthine, and to a lesser extent xanthine, composed the majority of metabolites which accumulated in the ISF of the ischemic region, accounting for greater than 95% of the total purine metabolites in the ISF after 20 min of ischemia. Despite the marked increase in ISF inosine, hypoxanthine, and xanthine levels, ISF uric acid levels did not increase in the ischemic region. Although CBF and SWT did not change in the nonischemic LC perfused area, there were small transient increases (two- to fourfold) in ISF adenosine, inosine, and hypoxanthine levels. In summary, these data demonstrate that purine metabolites accumulate rapidly in the ISF during myocardial ischemia.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Interstitial purine metabolites during regional myocardial ischemia. 235 25

The aim of this study was to differentiate myocardial reperfusion injury from that of ischemia. We assessed the role of the myocardial adenosine 5'-triphosphate (ATP) catabolites, hypoxanthine and xanthine, generated during ischemia and the early phase of reperfusion, in reperfusion injury by modulating adenosine transport and metabolism with specific metabolic inhibitors. This was followed by intracoronary infusion of exogenous hypoxanthine and xanthine. Twenty-four dogs instrumented with minor-axis piezoelectric crystals and intraventricular pressure transducers were subjected to 30 minutes of normothermic global myocardial ischemia and 60 minutes of reperfusion. In Group 1 (n = 7), normal saline was infused into the cardiopulmonary bypass reservior before ischemia and before reperfusion. Saline solution containing 25 microM p-nitrobenzylthioinosine (NBMPR) and 100 microM erythro-9-(2-hydroxy-3-nonyl)adenine (EHNA) was infused in Group 2 (n = 10) dogs. Group 3 (n = 7) dogs were treated exactly like those in Group 2 except, at the end of the ischemic period and immediately before releasing the cross-clamp, a solution of EHNA-NBMPR containing 100 microM hypoxanthine and 100 microM xanthine was infused into the aortic root. Left ventricular performance and myocardial adenine nucleotide pool intermediates were determined before and after ischemia. ATP was depleted by about 50% (p less than 0.05 vs. preischemia) in all groups after 30 minutes of ischemia. Inosine was the major ATP catabolite (9.29 +/- 1.2 nmol/mg protein) in Group 1, while adenosine (9.91 +/- 0.7 nmol/mg protein) was the major metabolite in EHNA-NBMPR-treated dogs (Groups 2 and 3). Hypoxanthine levels were fivefold more in Group 1 compared with Groups 2 and 3 (p less than 0.05). Left ventricular performance in Group 1 decreased from 76.8 +/- 7.6 to 42.9 +/- 9.8 and 52.3 +/- 8.4 dynes/cm2 x 10(3) (p less than 0.05), while myocardial ATP decreased from 30.9 +/- 2.2 to 17.2 +/- 1.0 and 16.5 +/- 1.0 nmol/mg protein during 30 and 60 minutes of reperfusion, respectively (p less than 0.05 vs. preischemia). Ventricular function in Group 2 dogs completely recovered within 30 minutes of reperfusion, and myocardial ATP recovered to the preischemic level at 60 minutes of reperfusion. In Group 3, left ventricular performance was depressed by 39% and 30% during 30 and 60 minutes of reperfusion (p less than 0.05), respectively, and myocardial ATP did not recover during reperfusion despite a significant intramyocardial adenosine accumulation.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Myocardial reperfusion injury. Role of myocardial hypoxanthine and xanthine in free radical-mediated reperfusion injury. 318 Apr 2

In acute experiments on open chest pigs 15 min occlusions of the left anterior descending coronary artery were performed, each occlusion followed by 45 min reperfusion. Myocardial ischaemia was defined by epicardial electrogram recorded from the border of the ischaemic area. Myocardial extraction of lactate and glucose as well as the extraction of FFA were measured before and at the 15th min of occlusion. Inosine (5 mg/kg/min) or 0.9% NaCl infusion was administered i.v. throughout the occlusion period. Inosine significantly diminished the number of ischaemic points and reduced an increase in R-wave voltage induced by coronary occlusion. Myocardial extraction of measured substrates was not significantly influenced by inosine administration. In conclusion, inosine decreases the area of ischaemic injury induced by acute coronary occlusion in the pig.
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PMID:The influence of inosine on the size of myocardial ischaemia and myocardial metabolism in the pig. 688 39

The purpose of this study was to compare interstitial fluid (ISF) levels of purine metabolites and lactate in the endocardium and the epicardium during graded regional myocardial ischemia and reperfusion. Anesthetized dogs were subjected to 60 min of regional myocardial ischemia induced by either partial or complete occlusion of the left anterior descending coronary artery (LAD), followed by 60 min of reperfusion. To sample ISF, cardiac microdialysis probes were implanted in the LAD-perfused myocardium; dialysate levels served as indexes of ISF concentrations. During severe ischemia, dialysate adenosine increased transiently in both the endocardium and epicardium, reaching maximal values at approximately 20 min of ischemia. Inosine, hypoxanthine, xanthine, and lactate increased most rapidly during the first 30 min of severe ischemia, after which the rate of increase was diminished. The ISF profiles of these metabolites were qualitatively similar during moderate ischemia, although the ISF levels achieved during ischemia were not as great. With both severe and moderate ischemia, ISF purines and lactate were greater in the endocardium than epicardium, consistent with a greater energy imbalance in the endocardium during ischemia. ISF total purines (the sum of the individual purine metabolites) were relatively stable until myocardial blood flow was reduced below 50 ml.min-1 x 100 g-1, after which ISF total purines increased in proportion to the severity of the blood flow deficit. These data suggest that functional and metabolic adaptations keep the myocardium in energy balance until blood flow is reduced below approximately 50% of control, and they attest to the usefulness of cardiac microdialysis for establishing transmural profiles of ISF metabolites.
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PMID:Endocardial and epicardial interstitial purines and lactate during graded ischemia. 816 Aug 5