Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:3.1.1.7 (acetylcholinesterase)
28,390 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The results of histochemical, histoenzymological, and fluorescence microscopy studies of the conductive tissue of the heart in acute myocardial infarction in 30 fatal cases are presented. Focal decrease in redox and hydrolytic enzymes, monoaminoxidase, and cholinesterase in elementa of the conduction system as well as changes in the pattern of fluorescence of the specific muscle cells were found. The intensity of metabolic lesions was more pronounced at early stages of myocardial infarction in those cases where the conducting pathways were proximal to the foci of necrosis.
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PMID:[Functional morphology of the heart conduction system in acute myocardial infarct]. 21 11

A course-wise administration of sodium selenate (30 gamma/kg), alpha-tocopherol (50 mg/kg) and of their combination in the same doses brings down the catecholamines content in the heart and suprarenals in the acute period of developing myocardial infarction (2nd day) with its subsequent normalization on the 14th day. Under the effect of these drugs the proportion of acetylcholine-like substances in the heart with experimental infarction rises at the expense of an accruing free (unbound with protein) fraction. The cholinesterase activity then gets intensified in the acute period and becomes normal by the 14th day.
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PMID:[Effect of sodium selenite, alpha-tocopherol and their combinations on the indices of the functional state of the heart regulation adren- and cholinergic systems in experimental myocardial infarct]. 59 96

210 male patients hospitalized for cardiac rehabilitation have been studied. As a result of age matching the sample was reduced to 190 patients: 72 patients with myocardial infarction, 90 patients with functional cardiovascular diseases, and 28 patients with angina pectoris. At the beginning and at the end of the 4 to 6 week rehabilitation program total lipids, cholesterol, triglycerides, phosphatides, GOT, GPT, LDH, HBDH, cholinesterase, aldolase, blood sugar, creatinine, electrolytes, hemoglobin, erythrocytes, leukozytes, and catecholamines were measured. In addition to the statistical comparison of the three groups and their specific change patterns, effects of body weight reduction and improvement of physical fitness were analyzed. The decrease of lipids is especially associated with weight reduction, whereas the decrease of enzyme activity and electrolyte concentration is accompanied as well with weight reduction as with the improvement of physical fitness.
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PMID:[Biochemical measures in cardiac patients: an analysis of change during rehabilitation (author's transl)]. 69 75

The effects of pharmacologic modulation of vagal activity on ischemic ventricular tachycardia were evaluated in 21 conscious dogs after permanent left anterior descending coronary artery (LAD) occlusion. Studies were done on spontaneous ventricular tachycardia (cycle length 383 +/- 100 msec, n = 21), 24 to 72 hours after LAD occlusion, and on inducible sustained monomorphic ventricular tachycardia (cycle length 251 +/- 30 msec, n = 6), 4 to 7 days after LAD occlusion. Edrophonium (1 mg/kg intravenously), a cholinesterase inhibitor, and methacholine (0.1 to 1 mg intravenously), a muscarinic agonist, had no significant effect on the rate or QRS morphology of either type of tachycardia, despite severe slowing of the sinoatrial rate. Similarly, atropine (up to 60 micrograms/kg intravenously) had no effect on the rate and QRS morphology of either type of tachycardia. In an attempt to enhance myocardial drug delivery to the ischemic and infarcted left ventricle, edrophonium (1 mg/kg) and methacholine (0.1 to 0.2 mg) were injected retrogradely through the great cardiac vein. This did not impart any significant therapeutic advantage over the systemic intravenous route. Sympathetic beta blockade did not affect the therapeutic outcome (n = 5) with either edrophonium or methacholine. It is concluded that direct or indirect enhancement of cardiac vagal activity has no effect on ischemic ventricular tachycardia in this model of subacute myocardial infarction. The lack of efficacy appears to be independent of myocardial drug delivery to ischemic ventricular site(s) and background sympathetic activity. Such a lack of efficacy may be caused by ischemia-mediated degeneration of vagal nerve terminals, by altered responsiveness of muscarinic receptors at infarcted arrhythmogenic myocardial sites, or both.
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PMID:The role of enhanced vagal activity on ischemic ventricular tachycardia: pharmacologic basis of inefficiency. 167 35

Acute heart ischemia induced by ligation of the left coronary artery is associated with variation in the activity of acetylcholinesterase, Na, K-ATPase and Ca, Mg-ATPase in rat erythrocytes. The maximum pronounced variations in the enzymatic activity and in the membrane capacity of erythroblasts for binding direct turquoise are recorded on the 7th day of the experimental myocardial infarction.
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PMID:[Changes in acetylcholinesterase and ATPase activity and certain structural features of the erythrocyte membrane in experimental myocardial ischemia]. 625 88

Dysfunction of the autonomic nervous system is of prognostic value for sudden death after acute myocardial infarction. Although the use of beta-blockers to counteract the adrenergic hyperactivity has been shown to decrease mortality in these patients, there have been no reports on the role of cholinomimetic drugs in the prognosis of patients after myocardial infarction. The present study was designed to investigate the effect of the administration of pyridostigmine bromide, a reversible anti-cholinesterase agent, on cardiac cholinergic activity assessed by the resting and reflex heart rate responses. Eight healthy volunteers were submitted to a conventional 12-lead electrocardiogram to obtain resting heart rate, and to three non-invasive cardiovascular tests: respiratory sinus arrhythmia, Valsalva maneuver and 4-sec exercise test. On two different days and following a randomized cross-over double-blind protocol, the experiments were performed before and 120 min after oral administration of either pyridostigmine bromide (30 mg) or placebo. Pyridostigmine increase (P < 0.05) the duration of the R-R intervals at rest (pre: 898 +/- 30 msec; post: 1019 +/- 45 msec; pre-placebo: 916 +/- 26 msec; post: 956 +/- 28 msec; P > 0.05). Although the duration of the R-R intervals during the autonomic tests was also increased (P < 0.05), the derived indexes of maximal fluctuation during the maneuvers did not change. These results indicate that oral pyridostigmine produces tonic cardiac cholinergic stimulation while exerting no effect on its reflex changes. Further studies are needed to address the potential role of the administration of pyridostigmine in the prognosis of patients with acute myocardial infarction.
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PMID:Resting and reflex heart rate responses during cholinergic stimulation with pyridostigmine in humans. 919 46

Heart failure is associated with attenuation of parasympathetic nervous function and enhanced renin-angiotensin activity. We tested whether there was a dysfunction in the efferent cholinergic neurotransmission in the heart of rats with chronic myocardial infarction (MI) and the potential role of angiotensin II (Ang II) receptors in such changes. Rats with MI and sham-operation were anesthetized, and heart rate (HR) reduction in response to vagal nerve stimulation was measured before and after losartan administration (10 mg/kg, i.v.) in the presence or absence of physostigmine to inhibit acetylcholinesterase. Infarcted rats had an average infarct size (IS) of 38% of the left ventricle (LV), depressed LV dP/dtmax, elevated LVEDP, and cardiac hypertrophy. Nerve stimulation (1-16 Hz) reduced HR in a frequency-dependent manner. The bradycardiac responses were significantly attenuated in infarcted versus control rats (p < 0.01), indicating an impaired efferent vagal tone. In contrast, the bradycardic response to exogenous acetylcholine was similar in both groups, implying an unchanged muscarinic receptor responsiveness in hearts with MI. HR response to nerve stimulation was potentiated by losartan in infarcted rats by 21 +/- 4 versus 4 +/- 2 beats/min (p < 0.01) but was unaffected in control rats. This effect of losartan was inversely related to the extent of attenuation of vagally mediated HR reduction. IS was correlated with both the extent of attenuation in vagally mediated bradycardia and the effect of losartan. In conclusion, the efferent vagal control of HR is attenuated in rats with MI and heart failure. This attenuation may be partly due to a presynaptic inhibition of acetylcholine release through the tonic activation, by Ang II, of neuronal AT1 receptors.
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PMID:Depression of efferent parasympathetic control of heart rate in rats with myocardial infarction: effect of losartan. 964 80

The active conformation is part of a conformational mixture with experimental activity Yexp, and is used in QSAR studies to extract more information regarding the ligand-receptor interaction. To reflect the relative amount (alpha) of the active conformation, we adjust Yexp: Yadj = Yexp - log alpha. We establish a quantitative structure-activity relationship (QSAR) between Yadj and 3D conformational characteristics for the acetylcholinesterase (AChE) hydrolysis rates of 25 acetic esters. The 3D-QSAR model was obtained using the adjusted multiconformational minimal steric/topologic difference (MTD-ADJ) method, optimizing the receptor map based on Yadj for each conformer. Yadj was updated during each step of the optimization process. alpha and Yadj are based on the Boltzmann distribution calculated using AMI (MOPAC 6.0) relative energies of the COSMIC 90 derived conformers. The MTD-ADJ results are: (i) the 3D-QSAR models obtained by this procedure have significant statistical parameters and are similar to the unadjusted (MTD-MC, using Yexp) models; (ii) the selected bioactive conformations are extended, occupy cavity vertices and, for the same structures, have the same MTD value; and (iii) the optimized conformational map of the neutral ligands obtained from the MTD-ADJ model fits well in the active site of the crystallographic structure of AChE (from Torpedo californica). We propose a neutral ligands binding site model for AChE. Our results show that MTD-ADJ, which can be implemented in any 3D-QSAR method, is capable of providing additional information regarding the active conformations, and can be used to gain further insight into the ligand-receptor models for which no structural data are available.
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PMID:MTD-ADJ: a multiconformational minimal topologic difference for determining bioactive conformers using adjusted biological activities. 969 Jan 73

Aged (25-27 months) Long-Evans female rats were distinguished according to whether they showed no significant impairment (AU), moderate impairment (AMI), or severe impairment (ASI) in a spatial reference-memory task. Young (3-5 months) rats served as controls. Electrically evoked overflow of tritium was assessed in hippocampal slices preloaded with [3H]choline or [3H]serotonin (5-HT). Nicotine-evoked overflow of tritium was measured after preloading with [3H]noradrenaline (NA). Choline acetyltransferase (ChAT) and acetylcholinesterase (AChE) activity, and concentration of monoamines were assessed in homogenates. Aged rats exhibited reduced accumulation of [3H]choline and [3H]5-HT, increased accumulation of [3H]NA, and weaker electrically evoked overflow of [3H]acetylcholine ([3H]ACh) and [3H]5-HT. The overflow of [3H]NA was not altered consistently by aging. Roughly, drugs acting presynaptically had comparable effects in aged rats: oxotremorine and CP 93,129 inhibited the overflow of [3H]ACh, CP 93,129 and UK 14,304 reduced that of [3H]5-HT. ChAT or AChE activity, and 5-HT concentration were not changed by age; NA concentration was reduced. When significant, changes were comparable in AU, AMI, and ASI rats. Data show that aging alters cholinergic and serotonergic hippocampal innervations, release of ACh and 5-HT, but not presynaptic release-modulating mechanisms. These alterations do not account for variability in water-maze performance of aged rats.
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PMID:Presynaptic modulation of acetylcholine, noradrenaline, and serotonin release in the hippocampus of aged rats with various levels of memory impairments. 1275 90

Coagulation factor XIII is a transglutaminase catalysing the crosslinking of fibrin chains as well as the formation of covalent links between several extracellular matrix proteins such as fibronectin, vitronectin and collagen. By mediating the incorporation of alpha2 antiplasmin into the fibrin network, this factor also interferes with fibrinolysis. Increased plasma factor XIII activity was reported by our laboratory 30 years ago in hypertriglyceridemic subjects who also displayed increased activity of serum cholinesterase, a marker of hepatic protein synthesis, and a delayed diluted, blood clot lysis time. Recent data in the literature emphasize a relationship between insulin resistance (metabolic syndrome) and increased plasma levels of factor XIII, confirming our results. It was also reported that a faster activation of this factor related to the Val 34 leu polymorphism provides protective effect against myocardial infarction and stroke, this effect being however negated in patients with insulin resistance and high plasma levels of plasminogen activator inhibitor-1. The pathogenic role of factor XIII in atherothrombosis seems to be bivalent. On the one side, an increased activity would favor the persistence of fibrin depositions and increase plaque burden, while on the other side it would reduce plaque vulnerability and the risk of downstream embolization.
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PMID:Coagulation factor XIII and atherothrombosis. A mini-review. 1552 18


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