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)

Four different oil-based diets were used in a feeding study involving rats to assess the relationship between the fatty acid composition of the dietary fat and its influence on erythrocyte membrane (EM) lipid composition and the activities of membrane-bound enzymes. Nutritionally adequate diets containing 20% groundnut (GNO), coconut (CO), safflower (SO), or mustard oil (MO) were fed to weanling CFY rats for 4 months. EMs were analyzed for total cholesterol, phospholipids, fatty acid profiles, and sialic acid content. Activities of membrane-bound enzymes such as Na+, K(+)-adenosine triphosphatase (ATPase), Mg(2+)-ATPase, Ca2+, Mg(2+)-ATPase, and acetylcholinesterase were also assayed. The activities of all membrane-bound enzymes, except Mg(2+)-ATPase, and sialic acid content were higher in the MO-fed group than in the rest of the groups. Ca2+, Mg(2+)-ATPase activity was distinctly lower in the SO-fed group than in the other groups. Cholesterol to phospholipid molar ratio was similar in all the groups. However, SO- and MO-fed groups displayed an increased cholesterol content and a higher degree of unsaturation in the membrane fatty acid composition. The higher membrane fatty acid unsaturation in the SO-fed group was principally due to linoleic (18:2) and arachidonic (20:4) acids, while in the MO-fed group it was mainly due to oleic (18:1), eicosenoic (20:1), erucic (22:1), and linoleic (18:2) acids. These results suggest a relationship between the quality of dietary fat, EM fatty acyl composition, and the activities of membrane-bound enzymes.
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PMID:Effect of dietary fats on erythrocyte membrane lipid composition and membrane-bound enzyme activities. 131 27

The antimalarial drug chloroquine is found to inhibit Na+, K(+)-ATPase, Ca2+, Mg(2+)-ATPase, Ca(2+)-ATPase, pNPPase and acetylcholinesterase activities in different organs of rat in vivo when injected for a certain periods of time. The inhibition seems to be due to the changes in the level of phospholipid, cholesterol and the fatty acid of the lipid and the alteration of the fluidity of the microsomal membranes. However, the enzyme activities return to the normal level in about 2-3 weeks after the discontinuation of the drug suggesting that the drug effect is reversible.
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PMID:The in vivo inhibition of transport enzyme activities by chloroquine in different organs of rat is reversible. 133 12

Denervated fast-twitch rabbit muscles were progressively losing their fresh weight and the yield of sarcotubular protein was increasing. The activity of Ca(2+)-ATPase was affected but very slightly, the basal Mg(2+)-ATPase and the Mg(2+)-ATPase/Ca(2+)-ATPase ratio however increased together with a simultaneous depression of the membrane-bound acetylcholinesterase activity. We did not observe any differences in density properties of sarcotubular fractions between control and denervated muscle. However, a relative enrichment in SM and H fraction could be seen after denervation with small changes in the content of the Ca(2+)-pump protein, increased levels of calsequestrin and cholesterol, mostly in the heavy and the SM fraction. After denervation the binding sites for 3H-PN-200-110 did not show any changes in receptor affinity, but the number of putative Ca(2+)-channels increased twice along with a depression of 3H-ouabain binding sites. We suggest that the denervation of fast-twitch muscle leads to the hypertrophy of the junctional sarcoplasmic reticulum and the T-system. Changes in the cholesterol content, in the number of putative Ca(2+)-channels and in Na+, K(+)-ATPase can affect the muscle contraction.
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PMID:Effects of denervation on the contents of cholesterol and membrane systems involved in muscle contraction in rabbit fast-twitch sarcotubular system. 165 Jul 29

The orientation of the enzyme Mg(2+)-ATPase (EC 3.6.1.3) in the transverse tubule (TT) membranes of skeletal muscle was investigated using highly purified chicken and rabbit TT vesicles. The percentage of sealed vesicles present in these preparations averaged 88 and 78%, respectively, as calculated from the detergent-induced increase in ouabain-sensitive (Na+, K+)-ATPase activity, ATP-dependent ouabain binding, and lactate dehydrogenase activity (sarcoplasmic enzyme trapped in the TT vesicles). Sidedness of the sealed vesicles, estimated from latency of 5'-nucleotidase, acetylcholinesterase, and adenylate cyclase, was predominantly right-side out (69-76%, chicken TT and 62-70%, rabbit TT). In both chicken and rabbit native vesicles, high Mg(2+)-ATPase activity was detected by addition of ATP to the extravesicular medium; this activity was increased 14-12% by alamethicin pointing to the external localization of the active site. Furthermore, the enzymatic activity resulted partially inhibited by treatment of the chicken TT vesicles with proteinase K or p-hydroxymercuribenzoate. Concanavalin A stimulated 4-fold the chicken TT Mg(2+)-ATPase activity, an effect not potentiated by detergent permeabilization of the intact vesicles, indicating that lectin-binding sites were also solvent accessible. This stimulatory effect was not observed in native or permeabilized rabbit TT vesicles. From these results we conclude that the TT Mg(2+)-ATPase is an ectoenzyme with its nucleotide-hydrolyzing site and glycosylated regions facing the extracellular space. Inhibitors of ion-motive ATPases did not modify the enzyme activity, suggesting a different physiological role for the TT Mg(2+)-ATPase which may be involved in the regulation of muscle fiber functions affected by extracellular ATP levels.
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PMID:Transverse tubule Mg(2+)-ATPase of skeletal muscle. Evidence for extracellular orientation of the chicken and rabbit enzymes. 166 Apr 76

Acute single dose (ip) administration of two rare earth elements like lanthanum chloride (250 mg/kg body wt) and neodymium chloride (200 mg/kg body wt) to chicks have been found to reduce the activity of certain erythrocyte membrane bound enzymes, viz. acetylcholinesterase, NADH dehydrogenase, Mg(2+)-ATPase, p-nitrophenyl phosphatase. Erythrocyte membrane bound glycosidases e.g. beta-D-glucosidase, beta-D-galactosidase and beta-D-glucuronidase were also reduced. Other components such as cholesterol and phospholipid residues were reduced but their ratio (cholesterol/phospholipid) remaining unchanged. Membrane sulfhydryl groups were also significantly inhibited by these rare earth elements.
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PMID:Chicken erythrocyte membrane: lipid profile and enzymatic activity under lanthanum chloride and neodymium chloride administration. 187 35

Lipid composition, fluidity, and Na+,K(+)-adenosine triphosphatase (ATPase), Mg(2+)-ATPase, and acetylcholinesterase (AChE) activities of erythrocyte membranes were examined in comparison to plasma lipid composition and lecithin:cholesterol acyltransferase (LCAT) activities in 39 patients with hepatic cirrhosis due to viral hepatitis (Child-Pugh class A, n = 12; class B, n = 13; and class C, n = 14). Plasma LCAT activities decreased and the plasma free-cholesterol to phospholipid molar ratio (C/PL) increased with progressive severity of hepatic cirrhosis. C/PL and fluorescence polarization (inverse of fluidity) of erythrocyte membranes also increased with disease progression (C/PL: Child-Pugh A, 0.911 +/- 0.010; B, 0.941 +/- 0.011; C, 0.979 +/- 0.028; and normal, 0.798 +/- 0.010; fluorescence polarization: Child-Pugh A, 0.348 +/- 0.002; B, 0.351 +/- 0.002; C, 0.355 +/- 0.002; and normal, 0.340 +/- 0.002). There was a correlation between C/PL and fluorescence polarization of erythrocyte membranes (r = .629, P < .001). Na+,K(+)-ATPase activity of erythrocyte membranes did not differ between cirrhotic patients and normal subjects. On the other hand, Mg(2+)-ATPase activity decreased in Child-Pugh C cirrhosis. AChE activity was decreased in Child-Pugh A cirrhosis, and decreased further in Child-Pugh B and C cirrhosis. AChE and Mg(2+)-ATPase activities correlated inversely with fluorescence polarization (r = -.652, P < .001 and r = -.381, P < .01, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Altered lipid composition and differential changes in activities of membrane-bound enzymes of erythrocytes in hepatic cirrhosis. 761 39

CBL/57 strain db/db mice exhibit type II (noninsulin-dependent) diabetes. The affected mice are markedly hyperinsulinemic, hyperglycemic, and hypercholesterolemic, and their serum K+ levels are decreased. The brains of the diabetic mice are significantly smaller than those of their lean, control littermates, but the protein concentration is normal. The low brain weight is accompanied by a loss of major fatty acid components within the whole brain, nerve endings, and mitochondrial membranes. Cholesterol levels are low in whole brain but are not significantly different from normal in the synaptosomal membranes. The phospholipid concentration is significantly decreased in whole brain homogenates, crude synaptosomal membranes, and crude mitochondrial membranes of the diabetic mice. In addition, the specific activities of membrane-bound synaptosomal acetylcholinesterase, Na+,K(+)-ATPase, and Mg(2+)-ATPase are decreased in crude synaptosomal membranes of the diabetic mice. The specific activities of carnitine palmitoyltransferase I and carnitine acetyltransferase are significantly increased in the crude mitochondrial fraction isolated from the brains of the type II diabetic mice, whereas the specific activity of pyruvate dehydrogenase complex is decreased. The specific activities of two other mitochondrial enzymes--monoamine oxidase B and citrate synthase--and a cytosolic enzyme--lactate dehydrogenase--are unaltered. The ability to synthesize cyclic AMP is markedly decreased in the brains of the diabetic mice. The concentrations of carnitine and of the amino acids, glutamate, aspartate, glutamine, and serine are unaltered, whereas glycine levels are significantly elevated in the brains of the db/db mice. The data suggest that in vivo the brains of the diabetic mice exhibit a decreased capacity for glucose oxidation and increased capacity for fatty acid oxidation. This hypothesis is supported by the finding that cerebral mitochondria isolated from the db/db mice oxidize [1-14C]palmitate to 14CO2 at a rate almost twice that of control mitochondria. The present findings emphasize the potentially serious alteration of brain metabolism in uncontrolled type II diabetes.
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PMID:Lipid metabolism and membrane composition are altered in the brains of type II diabetic mice. 772 1

The maximal rates (Vmax) of some enzyme activities related to synaptosomal energy metabolism were studied in different types of synaptosomes from cerebellar cortex of Macaca Fascicularis (Cynomolgus monkey). Different synaptosomal populations, namely "large" and "small" synaptosomes, were isolated from the anterior lobule of the cerebellar cortex of monkeys treated p.o. with dihydroergocriptine at the dose of 12 mg/kg/day before and during the induction of a Parkinson's-like syndrome by MPTP administration (i.v., 0.3 mg/kg/day for 5 days). The enzymes were chosen according to their regulatory role and as markers of the following metabolic pathways: (a) glycolysis ((hexokinase, phosphofructokinase, lactate dehydrogenase), (b) Krebs' (TCA) cycle (citrate synthase, malate dehydrogenase), (c) amino acid, glutamate metabolism (glutamate dehydrogenase, glutamate-pyruvate- and glutamate-oxaloacetate-transaminases), (d) acetylcholine catabolism (acetylcholinesterase) and (e) ATPases, i.e. Na(+)-K(+)-ATPase, Mg(2+)-ATP synthetase, Mg(2+)-ATPase, Ca(2+)-Mg(2+)-ATPase and Ca(2+)-ATPase Low and High affinity for Ca2+. The MPTP administration modified the activities of citrate synthase, malate dehydrogenase, Na(+)-K(+)-ATPase, acetylcholinesterase and glutamate-oxaloacetate transaminase only on selected types of synaptosomes. Pharmacological treatment by dihydroergocriptine was able to recovery at the steady-state levels the activities of these enzymes, thus demonstrating a partial protective effect on these biochemical parameters.
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PMID:Parkinson-like disease by 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) toxicity in Macaca fascicularis: synaptosomal metabolism and action of dihydroergocriptine. 817 63

Synaptic plasma membrane (SPM) vesicles represent a membrane fraction very useful in studying non-vesicular neurotransmitter release. The procedure described here to isolate SPM vesicles from a crude synaptosomal fraction of sheep brain cortex is quick, simple (ultracentrifugation in a discontinuous density gradient of dextran T110), and combines a high yield (130 micrograms/g brain) with a satisfactory grade of purification. The preparation of SPM vesicles consists of vesicles (approximately 0.54 +/- 0.8 micron diameter) delimited by a single membrane with the native orientation. We are able to ascertain these characteristics on the basis of morphology studies (electron microscopy observations), enzyme activities (Na+/K(+)-ATPase, Ca2+/Mg(2+)-ATPase, acetylcholinesterase and glucose-6-phosphatase), biochemical composition (lipid and protein analysis) and the tetrodotoxin sensitivity of the veratridine-induced gamma-aminobutyric acid (GABA) release. Isolating the SPM vesicles by the proposed procedure permits manipulating the ionic gradients across the membrane by changing the ion concentrations on either side or by utilizing specific ionophores. The vesicles retain their various activities, including their capacity for neurotransmitter uptake and release assays for at least 3 months, when preserved at -70 degrees C. Furthermore, the vesicles permit depicting the electrochemical gradients across the membranes into chemical and electrical components. We describe the use of the tetraphenylphosphonium cation (TPP+) to dissipate the membrane potential (delta psi) of the vesicles, while preserving ionic gradients. The characteristics of the lipid-soluble cation TPP+ allows a massive inflow of this cation into vesicular compartments and a consequent depolarization.
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PMID:Membrane potential manipulation in synaptic plasma membrane vesicles for studying neurotransmitter uptake and release. 938 41

The effect of different dietary fats with varying degrees of unsaturation and essential fatty acid composition, which are commonly consumed in India, on the activity of some important membrane-bound enzymes was assessed in different brain regions of rat. Four groups of male CFY weanling rats were fed nutritionally adequate diets containing groundnut, coconut, safflower or mustard oil as fat source at 20% level for 16 weeks. The synaptosomal, microsomal and myelin membranes were prepared from three brain regions, viz., cerebrum, cerebellum and brain stem from each group. The activities of Na+, K(+)-ATPase, Mg(2+)-ATPase and acetylcholinesterase were assayed and the fatty acid composition was determined in these subcellular membrane fractions. The safflower oil-fed group showed higher Na+, K(+)-ATPase activity in most membrane fractions than the coconut or mustard oil-fed groups. The Mg(2+)-ATPase activity was found to be similar amongst all groups in all the brain regions. The synaptosomal acetylcholinesterase activity was distinctly higher in coconut and groundnut oil-fed groups when compared to safflower or mustard oil consuming groups. Alterations in the activities of these subcellular membrane-bound enzymes are expected to exert a significant impact on the electrophysiological and metabolic functions of brain. Results of the present study show that depending on the nature of dietary fat the fatty acid composition of subcellular membranes is altered, which in turn could regulate the activity of membrane-bound enzymes that are vital for brain function.
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PMID:Influence of dietary fat on the activities of subcellular membrane-bound enzymes from different regions of rat brain. 941 40


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