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)

Evidence for in vivo antioxidative activity of reduced CoQ homologs has been presented. This came from studies with experimental endotoxemia in mice, reoxygenation of rat liver following ischemia, and reoxygenation of canine heart following 24-hour cold preservation. In radical-induced injury of hepatocytes, it has been first shown that reduced CoQ9 acts as a potential antioxidant regardless of its cellular concentration, whereas reduced CoQ10 acts in cells containing CoQ10 as the predominant homolog. The antioxidant activity of reduced CoQ homologs appears to be independent of that of alpha-tocopherol under the conditions employed.
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PMID:Antioxidant function of coenzyme Q. 129 10

Metabolic disturbances in the canine liver during warm ischemia by Pringle's method for 60 minutes and the role of Coenzyme Q10 (CoQ10), Prostaglandin E1 (PGE1) and ONO-3708, TXA2 receptor antagonist, were studied. Mongrel dogs were divided into five groups; control group, group of liver ischemia without drugs, groups of liver ischemia with CoQ10, PGE1 and ONO-3708 pretreatment. Metabolic rates of PGI2, TXA2, insulin, glucagon and glucose and production of lipid peroxides in the five groups were measured at the points before Pringle's procedure, 5 minutes, 60 minutes and 120 minutes after declamping. In the group of ischemia without drug administration, the hepatic metabolism of PGI2, TXA2, insulin and glucose were decreased after declamping. The metabolism of glucagon, however, was not disturbed by warm ischemia. The production of lipid peroxides increased at 5 minutes after declamping. In the groups of CoQ10, PGE1 and ONO-3708 pretreatment, changes of PGI2, TXA2 and insulin metabolism in the liver were improved, and an increased production of lipid peroxides by warm ischemia was normalized. This study suggests that CoQ10, PGE1 and ONO-3708 protect liver damage by warm ischemia as results of improvement of metabolic disturbances of PGI2, TXA2, insulin and suppression of lipid peroxides production.
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PMID:[Assessment for protective effects of CoQ10, PGE1 and TXA2 receptor antagonist (ONO-3708) on warm ischemic liver]. 138 60

We examined simple cold preservation of rat limbs in Euro-Collins' solution to elucidate the protective effect of coenzyme Q10 (CoQ10) on the ischemia-induced reperfusion injury in an ischemic extremity replant model. A total of 126 Lewis rat limb replants were performed. Limbs were amputated from donor rats and preserved at 4 degrees C in Euro-Collins' solution and were orthotopically grafted to isogeneic rats by microsurgical technique. In the experimental groups (n = 42), coenzyme Q10 (10 mg/kg) was injected intraperitoneally into the recipients about 1 hour before reperfusion. In the control groups (n = 84), the same dose of solvent was given by the same route. We evaluated vascular patency of anastomoses by direct observation or microangiogram and performed histologic examinations 7 days after replantation. In the control groups, the ischemic limit was 96 hours. Ischemic limbs treated with coenzyme Q10 showed a statistically significant (p < 0.05) improvement in vascular patency after 72 and 96 hours of ischemia. Histologically, bone viability with osteoblastic activity was maintained in coenzyme Q10-treated animals of the 72-hour ischemic group. We conclude that the protective effect of coenzyme Q10 on reperfusion injury is suggested in this replant model.
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PMID:Protective effects of coenzyme Q10 on ischemia-induced reperfusion injury in ischemic limb models. 141 41

Low-temperature electron paramagnetic resonance (EPR) spectroscopy and spin traps were used to measure paramagnetic species generation in rat hearts and isolated mitochondria. The hearts were freeze-clamped at 77 K during control perfusion by the Langendorff procedure, after 20-30 min of normothermic ischemia or 10-30 s of reperfusion with oxygenated perfusate. All EPR spectra measured at 4.5-50 K exhibited signals of both mitochondrial free radical centers and FeS proteins. The analysis of spectral parameters measured at 243 K showed that free radicals in heart tissue were semiquinones of coenzyme Q10 and flavins. The appearance of a typical "doublet" signal at g = 1.99 in low-temperature spectra indicated that a part of ubisemiquinones formed a complex with a high potential FeS protein of succinate dehydrogenase. Ischemia decreased the free radical species in myocardium approximately 50%; the initiation of reflow of perfusate resulted in quick increase of the EPR signal. Mitochondria isolated from hearts during control perfusion and after 20-30 min of ischemia were able to produce superoxide radicals in both the NADH-coenzyme Q10 reductase and the bc1 segments of the respiratory chain. The rate of oxyradical generation was significantly higher in mitochondria isolated from ischemic heart.
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PMID:Free radical metabolites in myocardium during ischemia and reperfusion. 165 95

This study was made in a canine isolated gracilis muscle model to measure directly the free radicals, to predict the severity of ischemia and reperfusion injury of the skeletal muscle by measuring its surface pH (mspH), and to determine the effect of Coenzyme Q10 (CoQ10) in reducing the extent of muscle injury. Animals were divided into three groups: group A (control, n = 10), group B (untreated, n = 10), and group C (CoQ10 treated, n = 10). In both groups B and C, 5 hr ischemia followed by 40 min of reperfusion was made. Free radicals were measured directly by electron spin resonance spectrometer (ESR) and mspH was measured using a pH microprobe. Serum creatine phosphokinase (CPK) was estimated before ischemia, 5 and 30 min after reperfusion. The extent of muscle injury was evaluated morphologically by Evan's blue dye exclusion test. ESR intensity in group B was 0.55 +/- 0.19 and decreased to 0.30 +/- 0.04 in group C (P less than 0.01). Rate of recovery of mspH was higher in group C (7.16 +/- 0.06) compared to group B (6.88 +/- 0.11, P less than 0.01) and CPK in group C was less (847 +/- 381 IU/liter) than in group B (1356 +/- 519 IU/liter, P less than 0.05) after 30 min of reperfusion. In group C the morphological muscle injury was less (37.8 +/- 5%) compared to group B (56.7 +/- 3.6%, P less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Free radical injury in skeletal muscle ischemia and reperfusion. 166 96

Using an isolated working rat heart model, the effects of DL-verapamil, ryanodine, gabexate mesilate (FOY), recombinant human superoxide dismutase (RH-SOD), and coenzyme Q10 upon myocardial protection were evaluated. Under conditions of normothermic ischemia, all these compounds, except RH-SOD, when added to the St. Thomas' cardioplegic solution at an optimal concentration, showed beneficial effects upon functional recovery and enzyme leakage. In contrast, the above compounds, except ryanodine and FOY, failed to improve the protective properties of the St. Thomas' cardioplegic solution under conditions of hypothermic ischemia. Our results indicate that calcium overload via the calcium channel and calcium-induced calcium release from sarcoplasmic reticulum (SR) may contribute to the onset of ischemic-reperfusion injury. However, under conditions of hypothermic ischemia, calcium-induced calcium release from SR plays a dominant role in calcium overload. Furthermore, intracellular calcium overload may activate proteases and result in the acceleration of myocardial injury.
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PMID:The effects of several pharmacologic agents upon postischemic recovery. 190 37

Gastric mucosal blood flow and its regulating factors were studied in normal and stressed rats. In addition, vascular regulating factors and the role of CoQ10 anion radical and SOD (superoxide dismutase) level in gastric mucosa were also investigated as well as the influence of 5-HT (5-hydroxytryptamine) on gastric mucosal blood flow. Gastric mucosal blood flow was measured by the hydrogen gas clearance method. The vascular pattern of the stomach was investigated by the infusion method with two-colored silicon rubber. CoQ10 anion radical and SOD levels in gastric tissue were assayed by electron spin resonance (ESR) and radioimmunoassay. The gastric mucosal blood flow decreased significantly early after the induction of stress. Impairment of gastric mucosal blood flow was highly correlated with 5-HT and CoQ10 anion radical and SOD levels. Reduction in gastric mucosal blood flow was consequently due to opening of arteriovenular shunt and hyperpermeability of true capillaries influenced by 5-HT. These results demonstrate that ischemia and reperfusion after reduction of the gastric mucosal blood flow resulted in the sequence of events that led to formation of acute gastric mucosal lesions.
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PMID:Gastric microcirculation and its regulating factors in stress. 194 Feb 4

The mechanism responsible for heterogeneity in tissue pH was investigated in perfused rat hearts subjected to ischemia/reperfusion insult, by correlating the time course of pH changes to the severity of vascular impairment. In 25 perfused hearts, myocardial pH was monitored by 31 P-NMR spectra. During ischemia, pH, which was 7.1 at the beginning of ischemia, progressively decreased and reached a steady level of 5.9 (5.9-compartment) after 40 minutes. In addition, another define peak of pH 7.1 (7.1-compartment) became evident after 50 min of ischemia. The 7.1-compartment grew higher with ischemic time and was only observed after 180 min of ischemia. Although reperfusion after 20 min of ischemia recovered pH, ATP, and creatine phosphate, reperfusion after 50 min left two Pi peaks, the 5.9- and 7.1-compartments; the former gradually decreased with a concomitant increase of the latter. Reperfusion after 180 min of ischemia with various pH levels did not shift the Pi peak from pH 7.1, suggesting that the perfusate did not reach that compartment, the impaired flow region. High coronary resistance and a heterogeneous staining pattern concomitant with a late appearance of the 7.1 component further supported this hypothesis. Myocardial coenzyme Q10 radical, an indicator of the tissue redox state, was also low in those hearts which were reperfused after 50 min of ischemia. Thus, the splitting of the Pi peak, caused by reperfusion after prolonged ischemia, represents the existence of a no-reflow region.
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PMID:The mechanism underlying heterogeneous pH in ischemic and reperfused myocardium. 206 3

This study tests the hypothesis that metabolic support of remote "nonischemic" myocardium during acute infarction will reverse the trend toward cardiogenic shock. Thirty-seven dogs underwent ligation of the left anterior descending coronary artery and 50% stenosis of the circumflex coronary artery. Irreversible ventricular fibrillation developed in 11 of them. The 26 survivors were observed for up to 6 hours; global and regional left ventricular function (cardiac index, stroke work index, ultrasonic crystals) and regional blood flow (radioactive microspheres) were measured. After 2 hours, eight dogs received an intravenous infusion of glutamate/aspartate, glucose-insulin-potassium, coenzyme Q10, and 2-mercapto-propionyl-glycine for 4 hours. Five dogs received the mannitol infusion to raise serum osmolarity 30 mOsm. Four additional dogs received the intravenous substrate infusions over 4 hours without undergoing ischemia. The substrate infusion for 4 hours caused no change in regional or global cardiac function in the four control dogs. Three of nine untreated dogs died of cardiogenic shock, and progressive left ventricular power failure occurred in the six others (40% decrease in cardiac index, 50% decrease in stroke work index, p less than 0.05) because of persistent dyskinesia in the left anterior descending region (-40% of systolic shortening, p less than 0.05) and hypocontractility in the circumflex region (48% of control systolic shortening, p less than 0.05), despite normal transmural blood flow in the posterior left ventricular wall (76 ml/100 gm/min). In contrast, in treated dogs, hypercontractility recovered in the circumflex segment (138% of systolic shortening) and stroke work index rose to control levels (91%) without a change in regional blood flow. Mannitol infusion did not improve hemodynamics or avoid the development of progressive left ventricular power failure. We conclude that cardiogenic shock after myocardial infarction is due, in large part, to impaired ability of "nonischemic" myocardium to maintain hypercontractility. This limitation can be prevented by metabolic support of viable muscle, and the data imply that intravenous substrate infusions may be helpful before definitive treatment (i.e., coronary artery bypass grafting) is undertaken.
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PMID:Studies on prolonged acute regional ischemia. V. Metabolic support of remote myocardium during left ventricular power failure. 250 26

Ischemic insult has been considered a cause of cellular injuries under certain circumstance, such as the disturbance of energy metabolism, the alternation of calcium homeostasis, the production of oxygen radical and the release of lysosomal protease. The present study was designed to clarify the pathophysiological effects of coenzyme Q10 (CoQ10), diltiazem, superoxide dismutase (SOD) and urinastatin on the development and progression of ischemic acute renal failure (IARF) of the rat. At 24 hours after reflow following 45 minutes ischemia, serum urea nitrogen, creatinine and fractional excretion of sodium were 99.3 mg/dl, 3.14 mg/dl, 5.95% respectively, in non-treated IARF rats. Renal ATP content was reduced to 0.91 micrograms/mg. prot. from 10.59 micrograms/mg. prot. at 10 minutes after ischemic insult, and remained at almost the same level throughout the entire 45 minutes ischemia. Although the subsequent blood reflow resulted in the recovery of ATP content, it was up to 50% of normal level at 24 hours after reflow following 45 minutes ischemia. During the ischemic period, the pathological changes were mild, whereas, after reflow, tissue involvement was mainly localized in the S3 segment of the proximal tubule. Major alteration were the loss of brush border, high amplitude swelling of mitochondria with matrical densities and fragmentation of the epithelial cell. At 24 hours after reflow, it was observed that renal function was superior in IARF rats treated with CoQ10, diltiazem, SOD and urinastatin. The treated rats also had higher ATP contents and showed less pathological changes than non-treated rats. Among these inhibitory agents, diltiazem exerted the most reliable effect. From these results, it was concluded that IARF was obviously caused by such pathophysiological mechanisms as mentioned above. Especially, Ca influx into the cells is one of the most important factors on pathogenesis of IARF.
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PMID:[Pathophysiological mechanism of ischemic acute renal failure: protective effect of coenzyme Q10, Ca channel blocker, superoxide dismutase and protease inhibitor against ischemic acute renal failure]. 274 96


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