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)

A prospective study of the accuracy of various diagnostic methods used in the detection of Hirschsprung's disease (syn. congenital intestinal aganglionosis, CIA) in 60 consecutive infants and children was done during the period 1972--76. Every patient underwent a barium enema, a rectal mucosal biopsy, which was prepared for both the demonstration of ganglia and for the assessment of acetylcholinesterase activity (ACE), and anal manometry was performed. In evaluating the clinical history, special emphasis was placed on signs of neonatal ileus. In the group of 10 patients with a definite diagnosis of CIA the results were almost uniform. In the 'non-CIA' group the search for ganglia in biopsy material proved non-confirmatory in nearly half of the cases studied due to the fact that specimens were taken too superficially. The findings pertaining to ACE, barium enema and the results of manometry were at variance or inconclusive of a final diagnosis in 10, 16 and 22% of the performed studies, respectively. The value given to neonatal history proved to be of the same order, i.e., 20% proved to be falsely positive.
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PMID:Diagnosis of Hirschsprung's disease. 53 12

This study is based on 17 neonates suffering from total colonic aganglionosis. The male:female ratio was 2:3 and there was a significant familial occurrence. The ages on admission varied between 1 and 90 days. The clinical presentation was extremely variable. Early diagnosis depends on clinical awareness of the condition in neonates who have intestinal obstruction or diarrhea, or both. The most important radiologic indication was retention of barium for 24 hours. Results of manometric studies were misleading. Suction biopsy of the rectum provided the only sure method of diagnosis, although determination of cholinesterase activity in the biopsy specimen and in the patient's serum was of some value. Two patients died before operation and two died from total colonic and small intestinal aganglionosis. Eight patients survived both the initial ileostomy and subsequent pull through operation. Of the various procedures utilized, the Lester Martin operation has proved to be the most satisfactory.
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PMID:Total colonic aganglionosis. 71 62

Soman, (pinacoloxymethyl-phosphoryl fluoride) (0.1-10 microM) an irreversible cholinesterase inhibitor, reversibly reduced the duration of calcium (Ca2+)- and barium (Ba2+) spikes without significantly affecting spike amplitude in sympathetic postganglionic neurons of the adult bullfrog (Rana catesbeiana). The soman-induced shortening of the spike duration was not prevented by pretreatment with either (+)-tubocurarine (100 microM) or hexamethonium (100 microM) and atropine (10 microM) and was also recorded from acutely-dissociated sympathetic neurons. These results suggest that soman has a direct action to decrease calcium entry through voltage-dependent channels activated during a spike. This effect may contribute to both the decrease in the duration of the spike after-hyperpolarization (AHP) and the enhanced neuronal excitability produced by soman in these neurons.
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PMID:Soman reversibly decreases the duration of Ca2+ and Ba2+ action potentials in bullfrog sympathetic neurons. 166 74

The authors have pharmacologically characterized longitudinal muscle contractility of the isolated rat jejunum chronically devoid of myenteric neurons. The myenteric plexus of a 3- to 4-cm segment of rat jejunum was ablated by serosal application of the cationic surfactant benzalkonium chloride (BAC). Fifteen days after treatment, both BAC-treated and untreated control jejunal segments were removed from each animal for pharmacological studies. BAC-treated tissues did not respond to the ganglionic stimulants nicotine, 1,1-dimethyl-4-phenylpiperazinium iodide and McN-A-343 or to the acetylcholinesterase inhibitor physostigmine. Short-pulse duration transmural electrical stimulation (0.1 msec) caused a frequency-dependent, tetrodotoxin-sensitive contraction in control but not BAC-treated tissues. Long-pulse duration transmural electrical stimulation (5.0 msec) contracted both control and BAC-treated jejunum. These contractions were partially reduced but not completely blocked by tetrodotoxin. To assess smooth muscle function, the mechanical responses to the muscarinic receptor agonist carbachol were examined. Carbachol contracted both control and BAC-treated tissues with maximal responses and ED50 values that were not significantly different. In addition, the maximal tension development produced by 10(-2) M barium chloride in similar lengths of control and BAC-treated jejunal segments was not significantly different. These studies demonstrate that chronic ablation of the myenteric plexus by serosal application of BAC essentially eliminates neuronally mediated responses without a concomitant alteration in longitudinal muscle contractility. Because nerve-mediated longitudinal muscle responses are lost despite the presence of an intact submucosal plexus in the BAC-treated jejunum, our data suggest that the motor neurons innervating the rat jejunal longitudinal muscle are located in the myenteric plexus.
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PMID:Pharmacological characterization of rat jejunal contractility after chronic ablation of the myenteric plexus. 242 79

1. The influence of castration on contraction of the guinea pig vas deferens induced by acetylcholine was investigated regarding facilitation of endogenous neurotransmitter release, changes in post-synaptic events and modification in acetylcholine metabolization. 2. Castration prolonged the duration of the isometric contraction of the vas deferens induced by acetylcholine (3 mM) but not the duration of that induced by barium chloride (10 mM). 3. Reserpinization (0.5 mg/kg) of normal and castrated guinea pigs did not change the time-course of acetylcholine-induced contraction in the vas deferens. 4. 4-Aminopyridine (0.05 mM) prolonged the contraction induced by acetylcholine and barium chloride. This effect was blocked by reserpine pretreatment, indicating that in the presence of 4-AP, both acetylcholine and barium release endogenous noradrenaline. Since there was no difference between the effects of 4-AP on organs from normal and castrated animals, prolongation of the acetylcholine-induced contraction is not related to an increase in neutransmitter release. 5. Total cholinesterase and acetylcholinesterase activities were reduced after castration and the time-course of carbachol contraction was not changed. Thus, this decrease in enzyme activity appears to play a relevant role in the prolongation of acetylcholine-induced contraction.
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PMID:The time-course of contractions induced by acetylcholine and barium in the vas deferens of normal and castrated guinea-pigs. 365 28

Since April 1973, 230 patients, who were suspected of Hirschsprung's disease, have been examined by rectal mucosal biopsy, barium enema and ano-rectal manometry. Their rectal mucosal specimens have been taken both from the regions 2cm upwards and just above the dentate line, and have been studied by means of acetylcholinesterase (AChE)-staining and hematoxylin-eosin (H-E)-staining. Specimens obtained by rectal full-thickness biopsies or operations were examined by means of AChE-staining, H-E-staining and silver-impregnation. Eleven out of the 230 patients were histologically diagnosed as hypoganglionosis. All rectal mucosas of hypoganglionosis showed a few small submucous plexus. According to the findings of nerve fibers, however, cases of hypoganglionosis were divided into three groups. The recognition of nerve fibers partially proliferated in rectal mucosa at the newborn age leads the diagnosis to type A. The type B is diagnosed as Hirschsprung's disease only through the recognition of proliferations of nerve fibers in rectal mucosa after the suckling age. In type C, no proliferation of nerve fibers can be recognized even after the suckling age. An accurate diagnosis of type C can be, therefore, made only through the examinations of myenteric plexus in full-thickness rectal specimen. On barium enema, a narrow segment was definite in 7 cases of hypoganglionosis, but was indefinite in the remaining 4 cases. The diseased segments of intestines were limited to the rectum or the rectosigmoid colon in 10 cases. Recto-anal sphincteric reflex showed an atypical reflex in 6 cases.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:[Clinical and histologic studies of abnormal intramural plexus with special reference to hypoganglionosis]. 371 73

The effects of dimethyl sulfoxide (DMSO) on subsynaptic response and quantal release of transmitter have been studied at the mammalian neuromuscular junction. Subsynaptically, at low concentrations (up to 1% by volume), DMSO prolongs the time course of decay of miniature endplate currents, (MEPCs), with no significant effect on the amplitude of the currents, which is consistent with an action of DMSO to inhibit acetylcholinesterase. At higher concentrations of DMSO (in excess of 1% by volume) the amplitude of MEPCs and the steady state response to carbamoylcholine (carbachol) are significantly reduced, which suggests an additional action of DMSO other than pure anticholinesterase activity. After pretreatment of the preparation with a low concentration of paraoxon, higher concentrations of DMSO decrease MEPC height and cause highly variable changes in the decay time course of the MEPC. The results suggest that DMSO concentrations in excess of 1% by volume have two distinct and opposite actions on the subsynaptic response; a pure anticholinesterase activity to enhance the response and a depressant effect which is similar to that caused by d-tubocurarine. Presynaptically, DMSO increased both the spontaneous release (measured as the frequency of miniature endplate potentials, fMEPP) and the evoked release (measured as the quantal content of endplate potentials). Both types of release were increased as an exponential function, with the same slope, of the DMSO concentration, suggesting a common mode of action on these two types of release. This action appeared not to be due to an effect on the disposition or effectiveness of calcium ions inside the terminal but, rather, was due to a fusogenic or global effect. In addition, the increase in fMEPP with DMSO was the same when external calcium was replaced by barium. At the concentrations studied, up to 8% by volume, DMSO did not cause any substantial depolarization of the nerve terminal or any appreciable change in the nerve terminal action potential. In a few experiments facilitation was studied at the frog neuromuscular junction and was unchanged by DMSO at concentrations which considerably enhanced transmitter release.
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PMID:The actions of dimethyl sulfoxide on neuromuscular transmission. 378 40

The contractile effects of barium, potassium, acetylcholine and acetyl-beta-methylcholine were studied in jejunum of 4, 12 and 20 month-old rats. The effects of age on the sensitivity and responsiveness of the jejunum to the agonists were examined using cumulative dose administration and measuring the pD2. The maximum contraction produced by the agonists and the sensitivity to barium and potassium were not modified by aging. In the middle-aged animals, the jejunum sensitivity to acetylcholine decreased while the sensitivity to acetyl-beta-methylcholine was not statistically different from that of 4 month-old rats. Since at this age (12 months) the acetylcholinesterase activity increased, the reduction in the sensitivity to acetylcholine could have been due to the increase in the activity of the metabolizing enzyme. Otherwise, in the jejunum from the older animals the sensitivity for both cholinoceptor agonists, acetylcholine and acetyl-beta-methylcholine, increased 5-fold when compared with the middle-aged animals. However, compared with the jejunum of 4 month-old rats the sensitivity to acetylcholine, to 20 month-old animals, was not altered while the sensitivity to acetyl-beta-methylcholine was increased. At this age (20 months), the jejunum acetylcholinesterase activity was increased when compared with that of 4 month-old rats and was not modified when compared with that of 12 month-old rats. The change in supersensitivity to cholinoceptor agonists could not have been due to an alteration in muscarinic receptor affinity, since the pA2 for atropine was not modified with increasing age. These results suggest that after an increase in acetylcholinesterase activity around month 12, the jejunum develops an adaptative supersensitivity to cholinoceptor agonists.
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PMID:Age-related changes in the reactivity of the rat jejunum to cholinoceptor agonists. 390 15

A 24-year-old Japanese woman with Hirschsprung's disease was subjected to the combination of barium enema, anorectal manometry, and a histochemical study of acetylcholinesterase (AChE) activity in rectal suction biopsy. The histochemistry revealed a marked increase of AChE positive nerve fibers. The importance of such a study is stressed in order to diagnose Hirschsprung's disease correctly, even in adults. A Z-shaped anastomosis as a modification of Duhamel's method was carried out. The postoperative course was uneventful and she now has normal bowel evacuation.
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PMID:Hirschsprung's disease in an adult. Special reference to histochemical determination of the acetylcholinesterase activity. 671 50

Nizatidine, a new histamine-2-receptor antagonist, stimulates gastrointestinal motility in dogs and gastric emptying of liquids in rats. Effect of nizatidine on gastric emptying of a solid meal was investigated using a novel gastric emptying model in rats. Male Wistar rats (weighing 200-300 g) were supplied with powdered food containing 30 w/w% barium 14 hr before the beginning of the experiment and x-ray photography of rat stomach was taken under light ether anesthesia. Gastric emptying was assessed by percentage of a decrease in area 30 min after drug was injected intraperitoneally. There was a positive correlation between the area of the gastric outline and the weight of the gastric contents (r = 0.94, P < 0.01). Ether anesthesia itself did not affect gastric emptying. Nizatidine increased gastric emptying dose-dependently (emptied percentage; vehicle: 4.9 +/- 1.5%, 1 mg/kg: 7.2 +/- 0.4%, 3 mg/kg: 10.4 +/- 2.0%, 10 mg/kg: 16.7 +/- 4.9%, 30 mg/kg: 25.7 +/- 7.4%). N-Desmethyl nizatidine (NDM) also stimulated gastric emptying, but nizatidine S-oxide, cimetidine, an famotidine had no significant effects on gastric emptying. Nizatidine and neostigmine, but not NDM, at a subthreshold dose accelerated gastric emptying treated with a low dose of acetylcholine (0.1 mg/kg). Atropine (2 mg/kg, -30 min) did not modulate the gastroprokinetic action of nizatidine, but blocked that of NDM. These findings suggest that this noninvasive method may allow measurement of gastric emptying of solids accurately and that nizatidine and NDM facilitate gastric emptying probably mediated by a direct and/or an indirect (acetylcholinesterase inhibition) cholinergic mechanism.
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PMID:Nizatidine accelerates gastric emptying of a solid meal in rats. 755 63


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