Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.1.1.7 (acetylcholinesterase)
 28,390 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The susceptibility to competitive ganglionic blocking agents such as hexamethonium (C6), tetraethylammonium bromide (TEAB), mecamylamine and d-tubocurarine (d-TC), of the superior cervical ganglion in cats with pancreatectomy and spontaneous diabetes or in animals treated with contrainsular drugs such as cortisone or dihydrochlorothiazide, was found to be decreased as compared to the reactivity of normal controls. The increased tolerance to ganglioplegics was not correlated with the elevation of the blood sugar level, and proved to be resistant to an acute administration of insulin. The results could not be explained by a decrease in the specific cholinesterase activity of the ganglionic tissue due to diabetes. Alteration of the peripheral autonomic synaptic transmission may be an early sign of diabetic neuropathy.
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PMID:Diabetes-induced alterations of autonomic nerve function in the cat. 3 32

Accumulation of acetylcholinesterase (AChE) and choline acetylase (ChAc) activities proximal to a tie placed on the sciatic nerve was measured in control, untreated diabetic, and insulin-treated diabetic rats. In the diabetic animals AChE accumulation was reduced by about 20% and ChAc accumulation by about 40%. Insulin treatment eliminated the impairment. It remains an open question whether these reversible functional changes in rat have any counterpart in the diabetic neuropathy of man.
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PMID:Fast and slow axoplasmic flow in sciatic nerve of diabetic rats. 5 67

Preparations from alloxan diabetic rats showed a reduced sensitivity to the neuromuscular blocking action of (+)-tubocurarine but no alteration in sensitivity to the depolarizing neuromuscular blocking drug decamethonium. Physostigmine was less effective in augmenting twitch height in preparations from alloxan diabetic rats and such preparations had a significantly lowered total cholinesterase activity compared with control preparations. An additional observation was a reduction in the effectiveness of the pre-junctionally active agent beta-bungarotoxin in producing neuromuscular blockade in physostigmine-treated preparations from alloxan diabetic rats. All the changes produced by alloxan administration were prevented by treatment with insulin.
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PMID:The effect of acute alloxan diabetes on the sensitivity of the rat skeletal neuromuscular junction to drugs. 21 52

The effects of pulsatile and nonpulsatile flow pattern on pancreas and liver blood flow were studied in nine dogs on cardiopulmonary bypass (CPB). Furthermore, plasma levels of glucose, insulin, glucagon, growth hormone, and cholinesterase were compared in 20 patients subjected to open heart surgery with either pulsatile or nonpulsatile perfusion. Impairment of liver and pancreas function was significantly greater at the end of CPB and 48 h afterwards with nonpulsatile flow as compared with the pulsatile flow pattern. A decrease of intestinal blood flow that was demonstrated in dogs subjected to nonpulsatile perfusion could at least in part be responsible for the difference in postoperative organ function observed in patients after CPB.
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PMID:[Comparative studies on pulsatile and continuous flow during extracorporeal circulation. Effects on liver function and endocrine pancreas secretion]. 45 49

The present study investigated the effect of insulin in vivo on the changes in the cooperativity of a membrane-bound enzyme. The allosteric inhibition by F- of the erythrocyte membrane acetylcholinesterase (acetylcholine hydrolase, EC 3.1.1.7) was studied during intravenous glucose tolerance tests in control and alloxan-induced diabetic rats. In the former group, the value of n decreased from 1.6 to 1.0 whereas it remained about 1.6 in the latter groups. Intravenous injection of insulin (30 U/kg) decreased the values of n in both groups. It is suggested that the in vivo insulin action on membrane cooperative enzymes could also take place in insulin target cells.
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PMID:Biomembrane cooperative enzymes. In vivo modulation of rat erythrocyte acetylcholinesterase by insulin in normal and diabetic conditions. 48 90

Distribution and activity of acetylcholinesterase (AChE) in the neurons of the central vagal nuclei at the level of the medulla oblongata were studied in intact and alloxan-diabetic adult male rats by Gomori's histochemical method. Peculiarities of intracellular distribution of the enzyme in the Nucl. dorsalis n. vagi (ND) and Nucl. ambiguus n. vagi (NA) of intact animals were demonstrated. Changes in the ratio of cholinergic neurons with moderate and strongly-positive AChE staining reactions were revealed in the ND of alloxan-diabetic rats. The dynamics of the changes attested to increased AChE activity of these neurons in response to insulin deficiency. The data obtained are additional evidence for the responsiveness of ND neurons to insulin deficiency, which was demonstrated earlier in alloxan-diabetic rats by karyometry (Akmayev and Rabkina, 1976 b). It is suggested that changes in the plasma glucose or insulin levels may be the stimulus that influences the activity of the ND cholinergic neurons. By means of this mechanism the central vagal nucleus at the medulla oblongata level may be implicated in the feedback control of insulin secretion.
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PMID:CNS--endocrine pancreas system. III. Further studies on the vagal responsiveness to insulin deficiency. 66 40

The exocrine and endocrine pancreas was investigated according to the fluorescence histochemical method of Flack and Hillarp. 1) Green fluorescent adrenergic fibers were regularly seen associated with arteries and arterioles in the exocrine pancreas. 2) Cholinergic fibers as shown by cholinesterase activity, were also found in the parenchyma of pancreas. 3) Yellow fluorescent cells scattered in the exocrine parenchyma and localized to a population of pancreatic islet cells with a characteristic distribution at the islet periphery was found. 4) By the fluorescence microscopic observation, inter-or intralobular pancreatic ducts, involving the zymogen granules, can also be seen after treatment with HCL vapor. 5) Yellow fluorescent cells, beta-cells containing insulin, remained at the Islet periphery. At present, the above mentioned yellow fluorescent cells are identified as containing HPP (Human pancreatic polypeptide) according to the immunofluorescence technique. With the use of the Falck and Hillarp histochemical technique ethionine induced pancreatitis in cats has been investigated. 1) After seven days of ethionine (5 mg/kg BW oral ad.) treatment, pancreas showed histochemical changes such as hemorrhage, fat necrosis, destruction of acinar cells and degranulation of zymogen from the parenchyma of pancreas. 2) Oral administration of ethionine for ten days induced severe degranulation, rupture of vessels, especially of veins and venules and later influenced arteries or arterioles. 3) Necrosis and fibrosis began to appear in the spaces between the cellular debris and marked pancreatic atrophy could be found. 4) The destruction of Islets of Langerhans can be found in the ethionine induced pancreatic parenchyma. On the other hand, an increased number of Islets of Langerhans was also observed in the site of lobule. 5) The presented findings may also suggest that the duration of administration of ethionine is more important factor than graded doses of ethionine in the production of ethionine is more important factor than graded doses of ethionine in the production of ethionine induced pancreatitis in cats.
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PMID:Fluorescence histochemical study of the pancreas in the cat. 79 42

We measured the cholinesterase activity in morning urines from 63 insulin-dependent diabetics and 27 controls. The total esterase (TotE) activity (Ellman's method) has been divided into aliesterase (AliE), pseudocholinesterase and acetylcholinesterase by means of two inhibitors, eserine and quinidine. Diabetics were divided in 2 groups according to the urinary albumin/creatinine ratio (mg/mmol, < 2 in group 1, > 2 in group 2). The urinary cholinesterase behavior was correlated with that of a known tubular lysosomal hydrolase, N-acetyl-beta-D-glucosaminidase (NAG). Compared to normals, in addition to a significant increase in urinary NAG in diabetes (in group 2 more than in group 1), TotE and AliE were also significantly raised (+36% and 109% of the controls, in group 1 as much as in group 2).
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PMID:Urinary cholinesterase activity is increased in insulin-dependent diabetics: further evidence of diabetic tubular dysfunction. 130 57

It has been reported that rat liver membranes contain a glycosylphosphatidylinositol-specific phospholipase C (GPI-PLC) which may be involved in generation of phosphoinositol-glycan, a putative insulin second messenger (Saltiel, A.R. and Cuatrecasas, P. (1988) Am. J. Physiol. 255, C1-C11). Using GPI-anchored acetylcholinesterase (AChE) from bovine erythrocytes as substrate, we attempted to isolate GPI-PLC from bovine and rat liver membranes. A major part of the GPI-anchor converting activity present in liver could be washed away from the tissue by extraction with detergent-free buffer. Solubilisation of the washed membranes with 0.25% (v/v) Nonidet P-40 and ultracentrifugation resulted in a considerable amount of detergent soluble GPI-anchor converting activity in the supernatant. Anion-exchange chromatography on a Fractogel TSK-DEAE column of detergent-soluble GPI-anchor converting activity revealed two distinct peaks eluting at 50-80 mM and 120-170 mM NaCl, respectively. Using [125I]TID-labelled mf-AChE as substrate, radiolabelled diradylglycerol was obtained with both peak activities. However, when the phosphatase inhibitors NaF and sodium orthovanadate were included in the assay systems, phosphatidic acid was detected in addition to diradylglycerol. Both GPI-anchor converting activities were Ca(2+)-sensitive and inhibited by heavy metal chelating agents. These results suggested the presence of two isoenzymes of GPI-PLD and a phosphatase, rather than a GPI-PLC activity, in liver. Further, it could be shown that the activity in the second peak was identical to GPI-PLD, abundantly present in serum, while the activity contained in the first peak seems to be genuine for liver cells and, thus, apparently represents a novel form of a GPI-PLD which is membrane-associated and distinctly different from the serum enzyme.
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PMID:A novel form of glycosylphosphatidylinositol-anchor converting activity with a specificity of a phospholipase D in mammalian liver membranes. 132 36

The arrival of the nerve impulse to the nerve endings leads to a series of events involving the entry of sodium and the exit of potassium. Restoration of ionic equilibria of sodium and potassium through the membrane is carried out by the sodium/potassium pump, that is the enzyme Na+,K(+)-ATPase. This is a particle-bound enzyme that concentrates in the nerve ending or synaptosomal membranes. The activity of Na+,K(+)-ATPase is essential for the maintenance of numerous reactions, as demonstrated in the isolated synaptosomes. This lends interest to the knowledge of the possible regulatory mechanisms of Na+,K(+)-ATPase activity in the synaptic region. The aim of this review is to summarize the results obtained in the author's laboratory, that refer to the effect of neurotransmitters and endogenous substances on Na+,K(+)-ATPase activity. Mention is also made of results in the field obtained in other laboratories. Evidence showing that brain Na+,K(+)-ATPase activity may be modified by certain neurotransmitters and insulin have been presented. The type of change produced by noradrenaline, dopamine, and serotonin on synaptosomal membrane Na+,K(+)-ATPase was found to depend on the presence or absence of a soluble brain fraction. The soluble brain fraction itself was able to stimulate or inhibit the enzyme, an effect that was dependent in turn on the time elapsed between preparation and use of the fraction. The filtration of soluble brain fraction through Sephadex G-50 allowed the separation of two active subfractions: peaks I and II. Peak I increased Na+,K(+)- and Mg(2+)-ATPases, and peak II inhibited Na+,K(+)-ATPase. Other membrane enzymes such as acetylcholinesterase and 5'-nucleotidase were unchanged by peaks I or II. In normotensive anesthetized rats, water and sodium excretion were not modified by peak I but were increased by peak II, thus resembling ouabain effects. 3H-ouabain binding was unchanged by peak I but decreased by peak II in some areas of the CNS assayed by quantitative autoradiography and in synaptosomal membranes assayed by a filtration technique. The effects of peak I and II on Na+,K(+)-ATPase were reversed by catecholamines. The extent of Na+,K(+)-ATPase inhibition by peak II was dependent on K+ concentration, thus suggesting an interference with the K+ site of the enzyme. Peak II was able to induce the release of neurotransmitter stored in the synaptic vesicles in a way similar to ouabain. Taking into account that peak II inhibits only Na+,N(+)-ATPase, increases diuresis and natriuresis, blocks high affinity 3H-ouabain binding, and induces neurotransmitter release, it is suggested that it contains an ouabain-like substance.
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PMID:In search of synaptosomal Na+,K(+)-ATPase regulators. 136 48


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