Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.1.1.8 (cholinesterase)
 12,691 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Experiments were conducted on rats; in depression of blood cholinesterase activity by 68.6 percent phthalafos proved to decrease the myocardial nicotinamide coenzymes content on account of reduction in the amount of the oxidized forms. In the liver phthalafos diminished the content of oxidized and reduced forms of nicotinamide coenzymes, decreased the level of adenylic nucleotides chiefly at the expense of ATP. Diproxim prevented the changes caused by phthalafos in blood cholinesterase reactivation to 47.5 percent. It is supposed that the capacity of diproxim to normalize the oxidative processes in the cell by acting upon the nicotinamide coenzymes and adenylic nucleotides underlies its antidote action.
 ...
PMID:[Effect of dipyroxime on the concentration of nicotinamide coenzymes and adenylate nucleotides in the myocardium and liver of rats poisoned with phthalophos]. 2 70

The subsynaptic area of mouse diaphragm fibres was hyperpolarized by 1--2 mV during local curarization of the junctional zone in the presence of the reversible anticholinesteraze prostigmine (6 X 10(-6) M), or after treatment of the muscle with organophosphate cholinesterase inhibitor Soman. In a solution containing 5 mM K+ the mean hyperpolarization was 1.1 +/- 0.27 mV at mean resting potential--70 mV. After adding 2 X 10(-5) M ouabain the hyperpolarization increased to 1.5 +/- 0.25 mV. Removal of potassium ions from the bathing medium also increased curare induced hyperpolarization to 1.80 +/- 0.40 mV. Reactivation of membrane ATP-ase by addition of K+ after a period in K+-free medium reduced the hyperpolarization to zero, where measurements were performed 10--20 min after the readdition. It was concluded that spontaneous non-quantal leakage of acetylcholine occurs at the mouse neuromuscular junction, as it does in the frog (ref. Katz and Miledi 1977). Conditions which block the Na+-K+-dependent ATP-ase of nerve terminals increased the continuous leakage of ACh and activation of the pump decreased it.
 ...
PMID:Electrophysiological examination of transmitter release in non-quantal form in the mouse diaphragm and the activity of membrane ATP-ase. 3 68

1. Female albino rats were treated with a total of 28 mg of chlormadinone acetate (CMA) for 28 days. In the adrenal cortex, the ovary, the vagina, and the uterus the activities of 3-beta-ol-steroiddehydrogenase, of dl-beta-OH-butric acid dehydrogenase, of alcaline and acid phosphatases, of DPN-diaphorase, of ATP-ase, and of non-specific esterases do not differ from untreated controls. 2. In the external muscle layer of the myometrium strong cholinesterase (ChE) activity was induced by C.M.A. A corresponding high ChE activity is normally found in immature rats or in estrus. 3. Furthermore, by treatment with CMA, ChE activity was induced in the tubular glands of the endometrium. This activity is found in the small parts of glomerate glandular terminals only but not in the rest of the glandular epithelium, nor in the epithelium of the cavum. It could be demonstrated that a corresponding ChE activity normally appears in the second third of pregnancy. The ChE activity induced by CMA was considerably higher and more widespread than during normal pregnancy. 4. It is concluded that in the endometrial glands a development similar to pregnancy is initiated by CMA. But development stops at the stage of ChE activity, thus leading to accumulation of ChE active cells.
 ...
PMID:[Enzyme histochemical studies on the rat adrenal cortex, ovary, uterus and vagina following chlormadinone acetate administration, especially cholinesterase activity in myometrium and endometrium]. 5 Feb 31

Exposure of rat brain Na+ + K+-ATPase (ATP phosphohydrolase E.C. 3.6.1.3) to concentrations of cassaine greater than 1 x 10(-4) M resulted in a poorly reversible inhibition of this enzyme. Inhibition did not require the presence of ATP and developed rapidly, but the final amount of inhibition observed was independent of time. The amount of inhibition observed at a given concentration of cassaine was reduced by increasing the concentration of membranes in the system. The inhibition of Na+ + K+-ATPase activity was associated with equivalent inhibition of the phosphorylation and (3H)-ouabain binding reactions of this enzyme, while the uninhibited enzyme was apparently kinetically normal. Concentrations of cassaine which produced this stable inhibition of Na+ + K+-ATPase had no effect on the Mg2+-activated ATPase or the NADH cytochrome-c-reductase activities of crude rat brain microsomal preparations. Cassaine inhibited the cholinesterase activity of rat brain microsomes with a Ki of about 5 x 10(-5) M, but his inhibition was fully reversible. The poorly reversible inhibitory actions of cassaine, thus, appeared specific for Na+ + K+-ATPase. Because this stable pattern of inhibition of the Na+ + K+-ATPase by cassaine required drug concentrations at least one hundred-fold greater than those which produce positive inotropic effects, it appears unlikely that this pattern of Na+ + K+-ATPase inhibition is involved in the cardiotonic actions of this drug.
 ...
PMID:Studies on the stable inhibition of Na+ + K+-ATPase by cassaine. 13 Feb 44

Nerve cell bodies, large and multipolar, were isolated in bulk with the least possible contamination from the pig brain stem. The activities of two neurobiologically important membrane enzymes, Na+, K+-ATPase, and acetylcholinesterase, in the isolated cell bodies were estimated. Na+, K+-ATPase [EC 3.6.1.4], more accurately called ouabain-sensitive ATPase of the nerve cell body, hydrolyzed 94 micronmoles of ATP per h per 100 mg of protein. This activity was one-fourth that in the brain stem. Nerve cell bodies contained a large amount of Ca2+, 275 micronmoles per 100 mg of protein, about half of which was calculated to exist as compounds other than calcium orthophosphate. However, the Na+, K+-ATPase of the nerve cell bodies was not stimulated by EGTA, in contrast to that of the brain stem. Acetylcholinesterase [EC 3.1.1.7] and cholinesterase [EC 3.1.1.8] activities were estimated separately by the use of the specific inhibitors Persidol and BW 284C51 dibromide. Acetylcholinesterase was almost completely responsible for the hydrolysis of acetylcholine in the nerve cell bodies isolated from the brain stem and little cholinesterase activity was detected. 1300-1400 micronmoles of acetylcholine was hydrolyzed per h per 100 mg of protein of the neuronal cell bodies; this activity was about four times higher than that in the brain stem. The differences between the specific activities of Na+, K+-ATPase, and acetylcholinesterase in theneuronal cell bodies and the brain stem are discussed in the light of electron microscopic analysis of the distribution of these enzymes and the preservation of the plasma membrane of the isolated cell bodies.
 ...
PMID:Biochemical characterization of the neuron. ATPase and acetylcholinesterase activities of neuronal cell bodies isolated in bulk from the pig brain stem. 14 Aug 66

The physiopathological effects were studied of a common high erucic acid rapeseed oil as well as of Janpol, a low erucic acid oil produced of a rapeseed variety selected in Poland. Its erucic acid content equals 2.8% of total fatty acids. The studies were carried out on white male Wistar rats, 25 days old at the beginning of experiment. These animals were divided into 6 groups fed the diets in which 10 or 20% of kcal well supplied either by high erucic acid rapeseed oil, by Janpol rapeseed oil, or by the sunflower oil. The experiment lasted 6 months. Following parameters were determined: increase in body weight, the weight of selected organs, blood serum alkaline phosphatase and pseudocholinesterase activities, blood serum cholesterol and triglycerides level, the content of corticosterone in the adrenal glands and blood plasma. The liver was studied histochemically for the activity of acid and alkaline phosphatases and of ATP-ase, as well as for the presence of lipids. Morphological studies of the myocardium comprised macroscopic, histological and electron microscopic investigation. The low erucic acid rapeseed oil Janpol seems to evoke less disturbances than the high erucic acid one. Supplied in the amount corresponding to 10% of total calories intake the former exerts the effect on the biochemical and morphological parameters similar to that of sunflower oil. It can be thus assumed that the low erucic acid rapeseed oil Janpol can be used in the feeding of man when served in the amount lower than 10% of total calories.
 ...
PMID:[Researches on the physiopathologic effects of rapeseed oil with high and low erucic acid content]. 15 22

Release of peroxidase from secretory cells of rat lacrimal gland upon cholinergic stimulation was studied in vitro with single lobules and isolated cells (lacrimocytes). Isolated lobules, kept in Eagle's medium, remain structurally intact and reaction product of peroxidase is confined to cisternae of rough endoplasmic reticulum, elements of the Golgi apparatus, and all secretory granules. Morphologically, exocytosis occurs by membrane fusion and discharge of granule content. The highest rate of peroxidase released from lobules is observed at 10(-4) M carbamylcholine. The specific activity of peroxidase released into the medium is fourfold higher as compared to the lobules. Release of peroxidase is suppressed by atropine when added before or after the addition of carbamylcholine. At 4 degrees C, no peroxidase release occurs upon cholinergic stimulation. The exocytotic release of peroxidase is dependent on energy supply, as indicated by substantial inhibition (at 37 degrees C) under anoxic conditions or in the presence of dinitrophenol, KCN, or carboxyatractyloside. Furthermore, the process is sensitive to colchicine and vinblastine. Isolated lacrimocytes, consiting of 95% secretory acinar cells, are prepared by digestion with collagenase, hyaluronidase, and trypsin. They retain the characteristic polarity of secretory cells in situ, and localization of peroxidase is the same as in lobules. Since isolated lacrimocytes respond to cholinergic stimulation in the same way as lobules, the receptors are not damaged by the isolation procedure and appear to be associated directly with the exocrine cell. Oxygen uptake by isolated lacrimocytes is about 14 nmol O2 X min-1 X 10(-6) cells; it is about doubled by uncoupling with dinitrophenol. Oxygen uptake rises by 20-30% above the resting rate upon cholinergic stimulation. This additional uptake is suppressed by atropine or by added cholinesterase, indicating that continuous receptor occupancy may be required for the energy demand by exocytosis. On the basis of the specific activity of peroxidase in the medium, the energy demand resulting from cholinergic stimulation is estimated to be 0.08 mumol ATP (or energy-rich phosphate bonds) per microgram of protein released from the lacrimocytes.
 ...
PMID:Exocytosis in secretory cells of rat lacrimal gland. Peroxidase release from lobules and isolated cells upon cholinergic stimulation. 95 71

Abolition of cholinergic inhibition in the heart of fresh-water bivalves in absence of cholinesterase can be attained by inactivation of the acetylcholine receptor (R). The role of Ca in this process was studied. Determination of Ca in the perfusate at different stages of cholinergic inhibition showed that the concentration of Ca increased during the sistolic arrest, and the initiation of beats was accompanied by binding of Ca. This coincided with the onset of ATP release and went on till the complete desensitization. The increase of external Ca concentration up to 1.10-2M increased the half-time of desensitization while the binding of Ca with EDTA decreased it and eliminated the ATP anti-acetylcholine effect. Another bivalent ion, UO2, which binds phosphate groups, competes with Ca. The role of Ca and ATP in chemical inactivation of the acetylcholine receptor is discussed.
 ...
PMID:[The role of Ca ions in desensitization induced by acetylcholine]. 120 72

1. Contractile responses and acetylcholine release evoked by nicotine in guinea-pig detrusor strips were determined by isotonic transducer and radioimmunoassay, respectively. Nicotine stimulated acetylcholine release and a contractile response in guinea-pig detrusor strips treated with the cholinesterase inhibitor, methanesulphonyl fluoride (MSF). Both actions evoked by nicotine were antagonized by the nicotinic receptor antagonist, hexamethonium but were insensitive to tetrodotoxin. 2. A sympathetic nerve blocker, guanethidine and a tachykinin antagonist, [D-Arg1, D-Pro2, D-Trp7,9, Leu11]-substance P (rpwwL-SP) partially inhibited the acetylcholine release evoked by nicotine to much the same degree. The inhibitory effects of guanethidine and rpwwL-SP on acetylcholine release were significantly greater than corresponding effects on the contraction evoked by nicotine. 3. In preparations treated with rpwwL-SP to block the tachykinin receptors, guanethidine had no effect on the response to nicotine. Conversely, after treatment with guanethidine to block release of a mediator from sympathetic nerve endings, nicotine-induced responses were not affected by rpwwL-SP. 4. Nicotine-induced contraction was reduced to 30% by the muscarinic cholinoceptor antagonist, atropine and completely abolished after desensitization of P2-purinoceptors with alpha,beta-methylene ATP in the presence of atropine. 5. A concentration-contractile response curve to neurokinin A (NKA) was shifted to the left after cholinesterase inhibition with MSF. Atropine abolished the facilitatory effect of MSF and partially inhibited contractions induced by NKA at 100 nM to 1 microM. The contractile responses to substance P methyl ester (SPOMe) and Tyr0-neurokinin B (Tyr0-NKB) were not influenced by MSF or atropine. 6. After desensitization of NK, tachykinin receptors with SPOMe or preincubation with senktide, the cholinergic component of the nicotine-induced contraction was the same as the control value (100%). 7. Our findings give further support to our previous results: nicotine stimulates acetylcholine release in a tetrodotoxin-resistant manner in guinea-pig bladder and acetylcholine release evoked by nicotine is increased by the coordinated action of sympathetic nerves and tachykinin(s). It is suggested that the tachykinin receptor subtype involved in acetylcholine release is NK,.
 ...
PMID:Contrasting effects of tachykinins and guanethidine on the acetylcholine output stimulated by nicotine from guinea-pig bladder [corrected]. 171 27

Mechanisms triggering the commitment of pluripotent bone marrow stem cells to differentiated lineages such as mononuclear macrophages or multinucleated megakaryocytes are still unknown, although several lines of evidence suggested correlation between cholinergic signaling and hematopoietic differentiation. We now present cloning of a cDNA coding for CHED (cholinesterase-related cell division controller), a human homolog of the Schizosaccharomyces pombe cell division cycle 2 (cdc2)-like kinases, universal controllers of the mitotic cell cycle. Library screening, RNA blot hybridization, and direct PCR amplification of cDNA reverse-transcribed from cellular mRNA revealed that CHED mRNA is expressed in multiple tissues, including bone marrow. The CHED protein includes the consensus ATP binding and phosphorylation domains characteristic of kinases, displays 34-42% identically aligned amino acid residues with other cdc2-related kinases, and is considerably longer at its amino and carboxyl termini. An antisense oligodeoxynucleotide designed to interrupt CHED's expression (AS-CHED) significantly reduced the ratio between CHED mRNA and actin mRNA within 1 hr of its addition to cultures, a reduction that persisted for 4 days. AS-CHED treatment selectively inhibited megakaryocyte development in murine bone marrow cultures but did not prevent other hematopoietic pathways, as evidenced by increasing numbers of mononuclear cells. An oligodeoxynucleotide blocking production of the acetylcholine-hydrolyzing enzyme, butyrylcholinesterase, displayed a similar inhibition of megakaryocytopoiesis. In contrast, an oligodeoxynucleotide blocking production of the human 2Hs cdc2 homolog interfered with production of the human 2Hs cdc2 homolog interfered with cellular proliferation without altering the cell-type composition of these cultures. Therefore, these findings strengthen the link between cholinergic signaling and cell division control in hematopoiesis and implicate both CHED and cholinesterases in this differentiation process.
 ...
PMID:Cloning and antisense oligodeoxynucleotide inhibition of a human homolog of cdc2 required in hematopoiesis. 173 28


1 2 3 4 5 Next >>