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Query: UMLS:C0011570 (depression)
 172,036 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The possible relationship of the atractyloside-sensitive adenine nucleotide translocase activity, oxidative phosphorylation, and the recovery of ventricular contractility following reperfusion of the ischemic isolated rat heart was studied. Five minutes of total global ischemia without reperfusion produced a significant depression in adenine nucleotide translocase in subsarcolemmal mitochondria (SLM), whereas a minimum of 10 min ischemia was required to observe a significant depression in interfibrillar mitochondria (IFM). Increasing durations of ischemia resulted in a progressively larger depression in translocase activity, with a maximum depression of approximately 75% seen in both populations following 20 min ischemia. In contrast, oxidative phosphorylation was totally unaffected in either mitochondrial population following up to 20 min of ischemia. We assessed whether translocase activity or oxidative phosphorylation were related to contractile recovery in hearts reperfused following various durations of ischemia. In SLM, translocase activity was further depressed following reperfusion compared with pre-reperfusion ischemic values, whereas with IFM only reperfusion following 5 min ischemia produced a further depression in translocase values. Oxidative phosphorylation rates of SLM and IFM were significantly depressed following reperfusion of ischemic hearts, although SLM exhibited a generally higher sensitivity in this regard. In reperfused hearts, an overall significant relationship was found between oxidative phosphorylation rate and adenine translocase activity as well as between translocase activity and post-reperfusion contractile recovery. These data show that ischemia can produce a significant depression in translocase activity in the absence of any change in oxidative phosphorylation. The results also suggest that the depression in mitochondrial ADP/ATP translocase and subsequent inhibition of oxidative phosphorylation in the reperfused heart may represent one of the important contributory mechanisms involved in cardiac failure and injury during acute ischemia and reperfusion.
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PMID:Relationship between oxidative phosphorylation and adenine nucleotide translocase activity of two populations of cardiac mitochondria and mechanical recovery of ischemic hearts following reperfusion. 254 94

The effects of i.v. nitroglycerin were studied by ECG and enzymatically in 16 patients (mean age 57.9 +/- 1.4 years) (NTG) in comparison with a control lot (c) of 17 patients (mean age 62.7 +/- 2.1 years) treated with dipyridamole and/or nifedipine (N), admitted in the first 4-10 hours after the onset of the first symptoms. The patients with heart failure and those with Q waves and CPK or LDH values greater than 2 x n were not admitted. NTG was administered in doses of 20 micrograms--60 microgram/hour for 24-96 hours and systolic AT (s) was kept under 10% of the basic values but not under 100 mmHg. Myocardial infarction appeared in 9 N-treated patients (54.86%) and 11 controls (58.25%) (p = 0.07). The size of myocardial necrosis was reduced in the N-treated patients. Peak serum CPK levels had considerably less increases in N (from 72.9 U to 73.4 U) (p greater than 00.5) versus C from 34.2 U to 364.5 U) (p less than 0.001). The sum of segmentary depression failed from 9.13 mm to 3.19 mm (p less than 0.05) in N, whereas in C the decrease was not significant (6.12 mm as against 9.38 mm; p greater than 0.05). The evolution was severe in C, as the angina crises (14 cases versus 2 cases, p less than 0.01) and the extension of the infarction (8 cases versus, 0; p 0.05) less than 0.05) appeared more frequently than in N. Only two patients in C died (p less than 0.05). Therefore, i.v. NTG administration in small doses in acute myocardial infarction leads to immediate disappearance of the anginal pain, lowers the extent of the myocardial necrosis and improves the clinical evolution.
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PMID:[The effects of nitroglycerin administered intravenously in acute myocardial ischemia]. 257 23

A case of coronary artery fistula with myocardial ischemia is reported. A 57-year-old-man was admitted to our hospital complaining of anterior chest pain on exertion. Submaximal Treadmill exercise showed the depression of ST segment in leads II, III, aVF, V5 and V6. 75% stenosis of right coronary artery (segment 2) and congenital coronary artery fistula originating from both the right and left coronary arteries were demonstrated by the coronary arteriography. One abnormal artery was originated from proximal portion of the right coronary artery (segment 1) and entered the pulmonary artery trunk. Another one was originated from proximal portion of the left coronary artery and terminated in angiomatous plexus which then communicated with the pulmonary artery trunk. We speculate that myocardial ischemia resulted from decreased right coronary blood flow due to coronary steal and proximal organic stenosis of right coronary artery. Recently, the reviews of coronary artery fistula are increasing, but coronary artery fistula with myocardial ischemia is relatively rare. This case was followed with medical therapy, because antianginal agents were effective. Operative coronary ligation may be necessary, if he has angina or high output heart failure during follow-up.
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PMID:[A case of coronary artery fistula with angina pectoris]. 259 26

A 14-year-old girl was admitted with chief complaints of edema and chest pain. She had hepatomegaly, but did not have heart murmur and accentuation of the pulmonary component of the second heart sound. The electrocardiogram showed right axis deviation, negative T wave in V3,4 and ST depression in III, aVF. But right ventricular hypertrophy was not dominant. Chest radiography showed a cardiothoracic ratio of 54% and a slight prominence of proximal pulmonary arteries. The edema was soon diminished only by the diuretics, but it appeared again without the diuretics. At the cardiac catheterization 3 months after the onset of symptoms, the pulmonary arterial pressure was 150/85 mmHg and the pulmonary resistance was 3,232 dyn/sec/cm5. The right atrial pressure was 9.5 mmHg and oxygen saturation at the pulmonary artery was 31.0%. Prostaglandin E1 reduced the pulmonary artery pressure only a little, but raised the systemic pressure. The patient was treated with several vasodilators, but her condition deteriorated rapidly and she developed severe right ventricular failure. She died only 8 months after the onset of symptoms and 5 months after the catheterization. At autopsy, histological examination demonstrated intimal fibrotic thickening of the small-sized pulmonary arteries and organizing thrombus. But there was not plexiform lesion. Heart failure was easily improved when she was first admitted. But after 3 months the cardiac catheterization revealed that her condition was already severe. Several vasodilators was not effective to such a rapidly progressive primary pulmonary hypertension.
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PMID:[A case of rapidly progressive pulmonary pulmonary hypertension in a 14-year-old girl]. 259 31

Isolated guinea pig hearts were perfused with Krebs buffer in the absence or presence of 10 microM adenosine for 60 to 120 min followed by a 15 min washout with adenosine-free buffer. The effects of isoproterenol on left ventricular dP/dt and heart rate were then determined. Perfusion with adenosine for a minimum of 90 min followed by washout resulted in a 40% depression of the dose-response curve of left ventricular dP/dt to isoproterenol. This depressed inotropic responsiveness persisted for at least 1 hr after cessation of adenosine perfusion. The heart rate response to isoproterenol was unaffected. Also, adenosine perfusion had no effect on ouabain inotropism. Measurement of adenosine in coronary effluent and in ventricular tissue by radioimmunoassay verified that no residual elevated adenosine remained following perfusion and washout. Moreover, isoproterenol-induced release of adenosine into the coronary effluent did not differ between control and adenosine-treated hearts. Addition of 100 microM theophylline, an adenosine receptor antagonist, to the adenosine containing buffer during perfusion prevented the depressed response to isoproterenol. In membrane fractions prepared from ventricles, beta receptors were assessed by (-) [125] iodocyanopindolol binding and neither the density of these receptors nor their affinity for agonists or antagonists was altered by adenosine perfusion. However, activation of adenylate cyclase by isoproterenol (10 microm) was significantly depressed in membranes from adenosine perfused hearts. These findings are consistent with a receptor mediated action of adenosine to produce persistent depression of catecholamine inotropism. Such an effect may be important in heart failure where myocardial levels of adenosine are elevated and circulating levels of catecholamines are high.
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PMID:Persistent desensitization of the heart to the inotropic action of isoproterenol by adenosine. 260 56

We measured cardiac functions by means of mechanocardiogram and echo-cardiogram in 93 patients with diabetes mellitus, excluding those who had apparent cardiac diseases, such as angina pectoris and cardiac failure. We used pre-ejection-period/ejection time (PEP/ET) as the index of the left ventricular systolic function and isovolumic relaxation time (IRT) as that of the left ventricular diastolic function. We compared the diabetic cases without complications to those with complications such as retinopathy, nephropathy, neuropathy and autonomic disorder. Conclusions obtained were as follows; An abnormal IRT was noted in the early stage of diabetic complications. The IRT was not normal among the subjects even when those with cardiac hypertrophy or ST-depression on the ECG were excluded. On the contrary, the PEP/ET did not show any abnormality in the early stage of diabetic complications until they advanced into, eg. renal failure or severe neuropathy. Our findings suggest that the disorder of the left ventricular diastolic function precedes that of the left ventricular systolic function, indicating the association of microangiopathy and autonomic disorder.
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PMID:[Left ventricular function in patient with diabetes mellitus--Evaluated by mechanocardiogram and echocardiogram]. 261 9

OPC-8212, a newly synthesized noncatecholamine, nonglycosidic, orally effective inotropic agent, has been shown to exert a potent cardiotonic action in acute administration to patients with heart failure. However, its long-term effect has not yet been established. Eight patients with dilated cardiomyopathy (New York Heart Association functional class II-III) were given a single dose of 60 mg of OPC-8212 daily for 4 to 8 weeks. OPC-8212 produced symptomatic improvement in four patients. Though there were no detectable changes in arterial pressure and left ventricular end-diastolic dimension, heart rate and end-systolic dimension significantly decreased after administration of OPC-8212. Baseline fractional shortening rose significantly and depression of shortening in response to acute pressor stress (afterload mismatch) was corrected after OPC-8212. The end-systolic pressure-dimension relation was shifted to the left with a steeper slope. These findings indicate that the inotropic state was substantially enhanced by the drug. No adverse effects were observed in any patient. Thus, the drug appears to hold promise for the chronic treatment of patients with moderate congestive heart failure who are essentially asymptomatic at rest, but develop severe impairment of cardiac function in a stressed state.
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PMID:Sustained inotropic effects of a new cardiotonic agent. OPC-8212 in patients with chronic heart failure. 264 27

Vascular responses to many physiological stresses are abnormal in heart failure. Increased peripheral resistance and a reduction in the vasodilator response to exercise and ischemia are examples of this abnormal vascular control. Such abnormal vascular control in heart failure is a result of interplay between neural, hormonal, and local vascular factors. This study was designed to test the hypothesis that a specific local mechanism, endothelium-dependent relaxation to acetylcholine (ACh), is depressed in experimental heart failure. Experiments were performed on 11 purebred beagles. Experimental heart failure was induced by rapid ventricular pacing for approximately 30 days. Femoral artery diameter was measured by sonomicrometry, and dose-response relationships to ACh, norepinephrine (NE), and nitroglycerin (NTG) were done before and after inhibition of cyclooxygenase by indomethacin. Heart failure resulted in a significant depression of ACh relaxation at all concentrations. In dogs with heart failure, indomethacin enhanced the dilation response to low concentrations of ACh. Constriction to NE and dilation to NTG were unchanged by heart failure. These data demonstrate that in the canine femoral artery endothelium-dependent dilation to ACh is depressed in experimental heart failure. Depression of endothelium-dependent vasodilation represents one local mechanism for abnormal control of the vasculature in congestive heart failure.
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PMID:Heart failure depresses endothelium-dependent responses in canine femoral artery. 270 66

The cardiovascular effects of 1,2-dihydro-6-methyl-2-oxo-5-(imidazo[1,2-a]pyridin-6-yl)-3-pyridine carbonitrile hydrochloride monohydrate (E-1020), a new nonglycoside, noncatechol cardiotonic agent, were investigated in dogs. In anesthetized dogs, E-1020 (10-100 micrograms/kg i.v.) dose-relatedly increased cardiac contractility (LV dP/dtmax), enhanced cardiac index and decreased systemic vascular resistance accompanying relatively small reduction in mean aortic pressure and a mild increase in heart rate. Coronary and femoral arterial blood flow were increased by either systemic intravenous or topical administration of E-1020. The degree of increase in myocardial oxygen consumption was only slight (10% at 30 micrograms/kg i.v.). The inotropic effect of E-1020 was not markedly affected by pretreatment with beta-adrenoceptor blockade, reserpine or other cardiotonic agents such as dobutamine or ouabain. In two experimental heart failure models induced by an excessive dose of propranolol or by coronary occlusion following volume-loading, E-1020 (30 micrograms/kg i.v.) rapidly reversed the cardiac depression. In chronically instrumented conscious dogs, E-1020 (30-100 micrograms/kg i.v. or 0.3-10 mg/kg p.o.) produced dose-dependent increases in LV dP/dtmax with minor increases in heart rate. E-1020 did not exacerbate arrhythmias of several experimental models in anesthetized dogs even at high dose of 100 micrograms/kg i.v. These results indicate that E-1020 is an intravenously and orally effective cardiotonic agent with vasodilating property, and that it may be beneficial in the treatment of acute and chronic congestive heart failure.
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PMID:Cardiovascular effects of the new cardiotonic agent 1,2-dihydro-6-methyl-2-oxo-5-(imidazo[1,2-a]pyridin-6-yl)-3-pyridine carbonitrile hydrochloride monohydrate. 2nd communication: studies in dogs. 271 42

Left ventricular (LV) contractile function and pump function were depressed in isolated working hearts from rats treated with either guanidinopropionic acid (GPA), an inhibitor of creatine influx, or the anthracycline antibiotic, adriamycin, for 6 and 10 weeks, respectively. In both groups of treated animals myocardial phosphocreatine content was lower than in control hearts, while ATP content was unchanged. Hearts of treated animals exhibited only a minor depression of cardiac output with a submaximal pressure load or during volume overload. However, at maximal pressure load GPA- and adriamycin-treated hearts performed 43% and 37% less pressure-volume work than control hearts. These changes were due both to decreased LV pressure development and diminished cardiac output. LV diastolic stiffness was significantly higher at the submaximal pressure load and the LV filling pressure area, which reflected LV filling, was lower in hearts of both treated groups. The differences in both indices were exaggerated when the maximal pressure load was applied. Limited LV filling due to incomplete myocardial relaxation appeared to represent the underlying cause of cardiac failure when afterload was increased. These results may be explained if adaptation of cardiac contractile function in some chronic cardiac diseases arises from a limited energy supply to the myofibrils.
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PMID:Adaptation of cardiac contractile function to conditions of chronic energy deficiency. 273 32


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