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Query: UMLS:C0018801 (
heart failure
)
72,216
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
The development of 31P-nuclear magnetic resonance (NMR) has enabled direct and non-invasive measurements of muscle metabolism. Serial measurements of the phosphocreatine/inorganic phosphate (PCr/Pi) ratio, which is closely related to the adenosine triphosphate/
adenosine diphosphate
(ATP/
ADP
) ratio and pH during and after forearm exercise were performed in 11 patients with chronic lung disease (CLD), nine patients with chronic
heart failure
(CHF) and eight control subjects. As compared with control subjects, the PCr/Pi ratio in the patients with CLD or CHF was lower during the recovery period and significantly lower at three and 4 min exercise. The pH values after exercise were lower in patients with CLD or CHF compared to control subjects. The PCr/Pi ratio at 4 min after exercise in the patients with CLD or CHF did not correlate with parameters of cardiac function or arterial and mixed venous oxygen tension. The arterial oxygen content and output in patients with CLD and CHF were significantly lower than that of control subjects. Nutritional parameters were not statistically different among the three groups. These observations suggest that metabolic abnormalities may be present in the skeletal muscles of patients with CLD and CHF that are not due to under-nutrition. These may result from reduced arterial oxygen output and, partially, from physical detraining.
...
PMID:31P-nuclear magnetic resonance evidence of abnormal skeletal muscle metabolism in patients with chronic lung disease and congestive heart failure. 155 77
It has been suggested that chronically reduced myocardial adenosine triphosphate (ATP) content causes contractile dysfunction in dilated cardiomyopathy. Because total adenine nucleotides (ATP,
adenosine diphosphate
and monophosphate) may reflect chronic changes in energy metabolism better than may ATP alone, myocardial ATP, and
adenosine diphosphate
and monophosphate were determined in endomyocardial biopsy specimens from 19 patients with dilated cardiomyopathy, and decreased left (30 +/- 2%) and right (34 +/- 3%) ventricular ejection fractions, and from 11 patients with ischemic cardiomyopathy (left ventricular ejection fraction 38 +/- 3%), and compared with those from 28 normal control subjects (ejection fraction greater than 55%) to assess myocardial energy metabolism in
heart failure
. Myocardial norepinephrine was measured simultaneously in the same biopsy specimens to assess if the myocardium studied for adenine nucleotide content was metabolically altered. Myocardial total adenine nucleotides as well as ATP levels in 19 patients with dilated cardiomyopathy (39 +/- 3 and 23 +/- 3 nmol/mg of noncollagen protein, respectively) were unchanged in comparison with those of control subjects (37 +/- 4 and 23 +/- 3, respectively); patients with ischemic cardiomyopathy were not significantly different (30 +/- 3 and 19 +/- 3, respectively). Myocardial norepinephrine in the same biopsy specimens from patients with dilated (5.8 +/- 1.1 pg/micrograms of noncollagen protein) or ischemic (5.7 +/- 1.3) cardiomyopathy was significantly decreased compared with that of normal control subjects (12 +/- 1.1).(ABSTRACT TRUNCATED AT 250 WORDS)
...
PMID:Myocardial adenine nucleotide concentrations and myocardial norepinephrine content in patients with heart failure secondary to idiopathic dilated or ischemic cardiomyopathy. 159 72
We have developed a model for characterizing calcium handling by the intact cardiac sarcoplasmic reticulum (SR) that yields data consistent with both mathematical simulations of in situ SR Ca2+ uptake and deduced behavior of the Ca2(+)-induced Ca2+ efflux channels in mechanically skinned single cardiac cells. In Na(+)-based media (37 degrees C, pH 7.2, 50 mM Pi, 10 mM MgATP, pMg 3.3, 10 mM phosphocreatine), SR 45Ca2+ uptake by digitonin-lysed rat myocytes as a function of free [Ca2+] peaked at pCa 6.2, declined until pCa 5.6 and increased again at lower pCa. When Ca2(+)-induced Ca2+ efflux was inhibited with 30 microM ruthenium red and 10 mM procaine, uptake was saturable with a Vmax of 160 +/- 5 nmol.min-1.mg-1, K0.5 of 500 nM free [Ca2+] and slope factor of 1.6. In K(+)-based media, maximum Pi- and oxalate-supported uptake increased to 220 and 260 nmol.min-1.mg-1, respectively. Without phosphocreatine, 45Ca2+ uptake declined under all conditions; this was correlated with a decrease in ATP/
ADP
. Vmax for 45Ca2+ uptake was increased 20% in hyperthyroid myocytes but depressed 30% in myocytes from
heart failure
-prone rats. In canine myocytes, Vmax was the same as in normal rat cells, but K0.5 was 830 nM. Without efflux inhibitors, ryanodine caused a concentration-dependent decline in net Pi-supported 45Ca2+ uptake at pCa 6.3 (K0.5 = 1 microM), while 10 microM ryanodine depressed uptake at all pCa between 7.2 and 5.6. Ruthenium red/procaine fully reversed this effect.
...
PMID:Calcium accumulation and release by the sarcoplasmic reticulum of digitonin-lysed adult mammalian ventricular cardiomyocytes. 169 80
In patients with
heart failure
there are distinct functional abnormalities in the myocytes themselves. This review deals with the deteriorations in the myocardial energy metabolism and the recently found alterations in the neurohumoral and hormonal signal transduction and signal realization within the cardiac cells. Beside the reduction in the volume of mitochondria in the overloaded myocardium the energy starvation is also reflected by a decrease in the content of high energy phosphates. Studies on nonfailing and failing human ventricular myocardium identified significant alterations in the neurohumoral regulation of the heart including the fluxes and the transport processes of Ca2+ as well as the beta-adrenoceptors, G-proteins, cAMP levels and cAMP-mediated processes. Recent data on the existence of auto-antibodies against the
ADP
/ATP translocator of the mitochondrial membrane and of stimulatory acting autoantibodies against i) the L-type calcium channel and ii) the beta 1-adrenoceptor, respectively, in patients with dilated cardiomyopathy, may open a new view in the etiology of
heart failure
and for consequences in the therapeutic concept of these diseases.
...
PMID:[Cellular and molecular mechanisms in heart failure]. 172 87
31P nuclear magnetic resonance (NMR) was used to examine the metabolism of skeletal muscle in rats 6-8 wk after myocardial infarction (MI). These in vivo measurements were supplemented by measurement of creatine, phosphocreatine (PCr), and ATP in freeze-clamped muscle using high-performance liquid chromatography (HPLC) and assays of key muscle enzymes to better define the muscle abnormality observed in
heart failure
. Resting PCr/(PCr + Pi) and pH were similar in MI rats and controls. Rats with MI had lower pH and PCr/(PCr + Pi) than controls during sciatic nerve stimulation at 1 and 2 Hz. These changes were more severe in rats with large (greater than or equal to 46%) infarcts, and changes in pH and PCr/(PCr + Pi) were correlated with infarct size. Free [
ADP
] in vivo was estimated from the NMR and HPLC measurements. [
ADP
] was increased in rats with large infarcts during nerve stimulation, implying a defect in oxidative metabolism. Citrate synthase, a mitochondrial enzyme, was reduced in rats with large MI. Citrate synthase levels were correlated with changes in PCr/(PCr + Pi) at 2 Hz. The NMR changes in skeletal muscle can be explained by reduced oxidative capacity of skeletal muscle, and this proposition is supported by the demonstration of reduced citrate synthase levels in skeletal muscle of rats with large infarcts.
...
PMID:Skeletal muscle metabolism in heart failure in rats. 187 70
Abnormalities in vasomotor tone, including enhanced vasoconstriction at rest and diminished vasodilation in response to various stimuli, develop as a consequence of chronic
heart failure
. This study was undertaken to evaluate whether a specific local mechanism, namely endothelium-derived relaxing factor (EDRF) activity, might be impaired in an experimental model of chronic
heart failure
. Segments of thoracic aorta (TA) and pulmonary artery (PA) were isolated from a group of rats that had hemodynamic evidence of
heart failure
10 weeks after ligation of the left coronary artery (n = 25) and from a group of sham-operated control rats (n = 18). Both endothelium-dependent and endothelium-independent vascular responses were assessed by exposing arterial segments to increasing concentrations of agonists. All studies were performed in the presence of 10 microM indomethacin to avoid the influence of vasoactive prostanoids. The dose-response curve for EDRF-mediated relaxation to acetylcholine was shifted rightward in rats with
heart failure
, and the concentrations of acetylcholine required to achieve 50% maximal relaxation (EC50) were increased compared with those of control rats in both TA and PA segments. Additionally, the dose-response curve for relaxation to
ADP
was shifted rightward with significantly increased EC50 in PA segments from rats with
heart failure
. In contrast, EDRF-mediated relaxation to the calcium ionophore A23187 was similar in the groups. Endothelium-independent relaxation to nitroglycerin was slightly increased in TA but not PA segments in the heart-failure group. Basal EDRF activity, as assessed by the increase in force after exposure to hemoglobin, was diminished in PA segments from rats with
heart failure
.(ABSTRACT TRUNCATED AT 250 WORDS)
...
PMID:Diminished endothelium-derived relaxing factor activity in an experimental model of chronic heart failure. 193 37
The prolonged noradrenaline treatment of rats (total dosage from 1 week--25 mg/kg), results in greatly reduced cardiac pump function and heart rate with a pronounced increase in left ventricular diastolic stiffness. These functional changes are associated with a deficiency of energy supply, especially depletion of phosphocreatine content. The taurine administration (100 mg/kg prior to 20 min noradrenaline injection) is accompanied by reliably less essential
cardiac insufficiency
. Moreover, the ATP,
ADP
level is normal and phosphocreatine content enhances by 15%.
...
PMID:[Norepinephrine-induced heart failure and the protective effect of taurine]. 208 93
The aim of the present study was to investigate whether or not alterations of Gs alpha can be detected with cholera toxin-induced
ADP
-ribosylation in myocardial membranes from patients with
heart failure
. Therefore, Gs alpha was radiolabeled by cholera toxin-catalzyed (32P)
ADP
-ribosylation with (32P)NAD as substrate. In membranes from left ventricular myocardium of six patients with dilated cardiomyopathy classified as NYHA IV and three samples from two non-failing donor hearts, labeling was too weak to allow detection of possible changes in the amount of Gs alpha. Therefore, the cytosolic small molecular weight G protein ARF (ADP-ribosylation factor), a cofactor for cholera toxin-induced
ADP
-ribosylation of Gs alpha, was partially purified from bovine cerebral cortex. ARF activity was quantified by its ability to enhance auto-
ADP
-ribosylation of cholera toxin A1-subunit. Gs alpha was identified by comparing the
ADP
-ribosylation patterns of myocardial membranes, membranes prepared from human leukemia (HL 60) and S 49 mouse lymphoma wild type cells (45 kDa-band present) with membranes of the Gs alpha-deficient S 49 variant cyc- (45 kDa-band missing). In the presence of ARF, specific radiolabeling of the Mr 45,000 subtype of Gs alpha was markedly enhanced. The amounts of Gs alpha as measured by cholera toxin-dependent (32P)-
ADP
-ribosylation in the presence of ARR were similar in failing and nonfailing human hearts. It is concluded that factors other than Gs alpha are responsible for the altered regulation of the adenylate cyclase complex in
heart failure
. Moreover, by enhancing cholera toxin-catalyzed
ADP
-ribosylation, endogenous ADP-ribosylation factor from bovine brain appears to be a useful tool to study Gs alpha even in tissues in which the labeling of Gs alpha is rather weak.
...
PMID:Improvement of cholera toxin-catalyzed ADP-ribosylation by endogenous ADP-ribosylation factor from bovine brain provides evidence for an unchanged amount of Gs alpha in failing human myocardium. 210 80
Atrial natriuretic factor (ANF) binding sites have been shown to be present on human platelet membranes. We investigated the effect of an infusion of ANF 5 pmol.kg-1.min-1 on platelet aggregation in whole blood ex-vivo in 8 normal volunteers. Spontaneous platelet aggregation, collagen (0.6-2 micrograms.m.-1)-induced or
ADP
(0.5-2.0 microM)-induced aggregation was not affected by ANF. Plasma aldosterone was however significantly attenuated by ANF. These results show that a pharmacological dose of ANF does not affect platelet aggregation in man. These results suggest that the high plasma levels of ANF normally achieved in chronic
heart failure
or acute myocardial infarction are unlikely to contribute to the platelet hyperractivity, often observed in these conditions.
...
PMID:Effect of atrial natriuretic factor on platelet function in whole blood ex-vivo in man. 215 20
There is substantial evidence that the failing heart is in an energy-depleted state. The imbalance between myocardial oxygen supply and demand might be the cause for adaptive metabolic changes seen in patients with severe chronic
heart failure
. By analyzing the lactate dehydrogenase (LDH) isoenzyme pattern, an increase of LDH5 and a decrease of LDH1 was seen in myocardium from patients with chronic
heart failure
. Additionally, the concentration of the
adenosine diphosphate
(
ADP
)/adenosine triphosphate (ATP) carrier was significantly elevated. After treatment with the angiotensin-converting enzyme inhibitor enalapril in 33 patients with chronic
heart failure
, LDH1 increased from 38.7 +/- 6.7 to 42.3 +/- 5.5 (p less than 0.005), paralleled by a decrease in LDH5 from 20.8 +/- 7.0 to 15.8 +/- 4.7 (p less than 0.001). The
ADP
/ATP carrier concentration also decreased significantly within the normal range. There was a good correlation between the hemodynamic data and the LDH isoenzyme pattern. The shift of the LDH isoenzyme pattern and the decrease of the
ADP
/ATP concentration can be taken as an indication for an improvement of the myocardial energy balance in chronic
heart failure
with angiotensin-converting enzyme inhibitor therapy.
...
PMID:Effect on the myocardial energy metabolism of angiotensin-converting enzyme inhibition in chronic heart failure. 232 55
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