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 origins, distribution, and cellular targets of the septo-hippocampal projections are reviewed. It appears that the distribution of acetylcholinesterase-positive neurons in the medial septum and diagonal bands and those cells labelled after injections of horseradish peroxidase into the hippocampus coincide; however, the possibility of a non-acetylcholinesterase septal projection remains. Good agreement is found between the distribution of hippocampal acetylcholinesterase and the patterning of silver grains after injection of [3H]leucine into the medial septum. A major target of septal efferents to the hippocampus is the interneuron population; the possibility of septal mediation of intrahippocampal circuitry via this anatomical arrangement is discussed.
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PMID:Anatomical and functional aspects of the septo-hippocampal projections. 8 25

Pathological changes of the fusimotor endings in parkinsonism, motor neuron disease and myasthenia were examined by the acetylcholinesterase technic on serial sections. In parkinsonism, the diffuse endings, which are thought to be supplied by the static gamma nerve fibers, showed remarkable enlargement, while en plaque and en grappe endings were atrophic. In motor neuron disease, en plaque and en grappe endings, which are thought to be innervated by the beta nerve fibers and dynamic gamma nerve fibers respectively, revealed marked atrophy. However the diffuse endings were normal. In myasthenia gravis and myasthenic syndrome (Eaton-Lambert syndrome), en plaque and en grappe endings were atrophic, though only the diffuse endings were spared. The significance of these changes in the fusimotor endings is discussed.
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PMID:Histochemical study of the muscle spindles in parkinsonism, motor neuron disease and myasthenia. An examination of the pathological fusimotor endings by the acetylcholinesterase technic. 8 59

1. In rabbit peroneal nerves incubated in vitro at 37 degrees C, acetylcholinesterase (AChE) activity accumulated at both borders of a short region cooled to 5 degrees C. Accumulation was unaffected by concentrations of cycloheximide that inhibited 86% of local protein synthesis, as measured by the incorporation of [3H]leucine. It is probable that the local changes in enzyme activity during incubation reflected redistribution of the enzyme by axonal transport. 2. AChE activity accumulated almost three times faster at the proximal than at the distal border of cooled regions. This suggests that three times more enzyme is normally exported from nerve cell bodies than is returned to them, as though most of the transported AChE were degraded or secreted from distal parts of the neurones. The rates of accumulation of enzyme activity were consistent with average velocities of transport of 24 mm/day in the distal (orthograde) direction and 8.6 mm/day in the proximal (retrograde) direction. 3. When nerves that had been locally cooled for 3 hr were rewarmed to 37 degrees C, the accumulated AChE activity moved rapidly away from the cooled region. More than half of the activity appeared in a wave moving distally with a maximum velocity of 400 +/- 35 mm/day. A smaller wave moved proximally with a maximum velocity of 288 mm/day. 4. The observed behaviour of AChE is direct evidence that a small amount of this enzyme, probably less than 10% of the axonal content, is normally transported away from cell bodies as rapidly as any substance known. A still smaller amount of the enzyme is subject to an almost equally rapid retrograde transport. However, 85% of the AChE in peripheral nerve appears to be stationary, which probably explains why the average velocity of transport of this enzyme is so low.
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PMID:Rapid orthograde and retrograde axonal transport of acetylcholinesterase as characterized by the stop-flow technique. 8 68

1. Rabbit peroneal nerves were exposed to echothiophate, a quaternary ammonium inhibitor of acetylcholinesterase (AChE), and 217-AO, its tertiary analogue, in an attempt to characterize the localization of the enzyme. Although 217-AO readily inhibited AChE throughout the nerves, echothiophate spared significant amounts unless the tissues had first been homogenized. Notably, doses of echothiophate inhibiting 84% of the total AChE inhibited only 30% of the rapidly transported enzyme, suggesting that AChE was distributed between compartments differing greatly in their accessibility to this drug. 2. Since charged molecules penetrate cells poorly, it seemed likely that the more accessible compartment of AChE was external, perhaps consisting mainly of enzyme incorporated into the outer surface of the axolemma. If one assumes that the inhibition of the transported enzyme accurately reflected the inhibition throughout the inaccessible compartment, it can be calculated that external AChE comprised about 80% of the total. 3. The quasi-irreversible inhibition of AChE by echothiophate was used to probe the dynamics of the external enzyme. Locally exposing nerves to this drug in vivo markedly inhibited the AChE in a short region, which subsequently recovered with a half-time of about 5 days. Recovery appeared to reflect delivery of new enzyme into the inhibited region rather than spontaneous reactivation or local synthesis of AChE. Surprisingly, the zone of inhibition neither broadened nor moved noticeably for at least 8 days. This implies that external AChE is largely fixed in place and must be renewed locally, presumably by incorporation of rapidly transported enzyme from the internal compartment.
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PMID:On the origin and fate of external acetylcholinesterase in peripheral nerve. 8 69

Raised levels (greater than or equal to 4.5 munits/ml) of acetylcholinesterase (AChE) activity in amniotic fluid at 14--23 weeks of pregnancy were significantly associated with open fetal neural-tube defects. Out of 72 pregnancies correctly classified by the amniotic-fluid alpha-fetoprotein (A.F.P.) test, 2 of 56 without neural-tube defects and all 16 with open neural-tube defects (8 with anencephaly and 8awith open spina bifida) had raised levels of AChE. Out of 5 pregnancies misclassified by the A.F.P. test (4 without neural-tube defects and 1 with open spina bifida), only 1 was misclassified by the AChE test--namely, one of those without a neural-tube defect. Thus, only 3 of the 77 pregnancies tested were misclassified by the quantitative AChE test. A qualitative test for an isoenzyme of AChE found in cerebrospinal fluid correctly classified these 3 pregnancies. These findings suggest that the analysis of AChE in amniotic fluid may be a useful test in the diagnosis of open neural-tube defects.
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PMID:Amniotic-fluid acetylcholinesterase as a possible diagnostic test for neural-tube defects in early pregnancy. 8 32

Leptophos (O-[4-bromo-2,5 dichlorophenyl] O-methyl phenylphosphonothioate) (PhosvelR) was administered orally to chickens and rats in doses of 0.5 and 5.0 mg/kg/day for 26 weeks. Hens fed 5.0 mg/kg, except one, showed ataxia and became paralysed in the legs at varying times from 8 to 19 weeks. A fifth hen showed ataxia early in the experiment but recovered fully for the remainder of the experiment. Rats fed both doses and chickens fed 0.5 mg/kg showed no signs of delayed neurotoxicity. All hens fed 5.0 mg/kg stopped laying by about the third week. Animals of both species fed 5.0 mg/kg either lost weight (chickens) or gained less weight (rats) than the others. Erythrocyte acetylcholinesterase (AChE) of the chickens given both doses was significantly depressed at first, then increased, and later dropped to control levels. AChE of rats fed 0.5 mg/kg was significantly inhibited but soon recovered to within control levels. On the other hand, the AChE of rats fed 5.0 mg/kg was inhibited throughout the experiment. Plasma cholinesterase (ChE) of both species was first inhibited and then recovered erratically for both insecticide concentrations. Histological alterations in the spinal cord of paralysed hens included axon and myelin degeneration in the ventral, lateral and posterior columns. In the paralysed hens, 79% of the neurotoxic esterase in the brain were inhibited, whereas in the non-paralysed hens (including the one non-paralysed hen receiving 5.0 mg/kg/day) and all rats only about half as much was inhibited.
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PMID:Neurotoxic effects of leptophos (PhosvelR) in chickens and rats following chronic low-level feeding. 8 38

The distribution of adrenergic, cholinergic and peptidergic nerves in the feline eustachian tube was studied using histochemical techniques. Adrenergic, acetylcholinesterase-positive and vasoactive intestinal polypeptide immunoreactive nerves were numerous in the tubal wall. All three types of nerve fibers occurred in the subepithelial layer, around small blood vessels and around the acini of seromucous glands. No nerves displaying substance P or enkephalin immunoreactivity were observed.
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PMID:Innervation of the feline eustachian tube. 8 26

The extrinsic innervation of the abdominal organs in neonatal and adult female rats is described. Mainly an in toto acetylcholinesterase method was used; moreover, formaldehyde-induced fluorescence and acetylcholinesterase were demonstrated in sections. The major splanchnic nerve has its origin in the ninth and tenth thoracic sympathetic trunc ganglia. In the major splanchnic nerve a suprarenal ganglion is present. Sometimes the minor splanchnic nerve, arising from the tenth thoracic ganglion, joins the distal part of the suprarenal ganglion. The left and right major splanchnic nerves join the left and right celiac ganglia in the plexus. The left celiac ganglion is always bigger than the right one. The celiac plexus and the celiac inferior mesenteric plexus are joined by the intermesenteric plexus. Para-aortic nerves, originating in the caudal part of the thoracic sympathetic truncs, also join the abdominal prevertebral plexuses. The lumbar splanchnic nerves, not symmetrical in their origin, join the prevertebral plexuses and give off branches to the abdominal organs. The suprarenal glands receive bundles of nerve fibers, sometimes ganglionated, from the suprarenal ganglion. The kidneys are innervated from the celiac plexus, the upper lumbar splanchnic nerves and the intermesenteric plexus. The ovarian nerves are derived from the celiac plexus, the intermesenteric plexus and the upper lumbar splanchnic nerves. Bundles of nerve fibers run from the suprarenal ganglion in the celiac plexus in the direction of the suspensory ligament of the ovary. In many respects this description is at variance with existing literature on the autonomic innervation in the rat. These differences with the standard literature are relevant to those workers engaged in experiments on the sympathetic innervation of abdominal viscera.
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PMID:The extrinsic innervation of the abdominal organs in the female rat. 9 Apr 40

Basal lamina (BL) ensheathes each skeletal muscle fiber and passes through the synaptic cleft at the neuromuscular junction. Synaptic portions of the BL are known to play important roles in the formation, function, and maintenance of the neuromuscular junction. Here we demonstrate molecular differences between synaptic and extrasynaptic BL. We obtained antisera to immunogens that might be derived from or share determinants with muscle fiber BL, and used immunohistochemical techniques to study the binding of antibodies to rat skeletal muscle. Four antisera contained antibodies that distinguished synaptic from extrasynaptic portions of the muscle fiber's surface. They were anti-anterior lens capsule, anti-acetylcholinesterase, anti-lens capsule collagen, and anti-muscle basement membrane collagen; the last two sera were selective only after antibodies binding to extrasynaptic areas had been removed by adsorption with connective tissue from endplate-free regions of muscle. Synaptic antigens revealed by each of the four sera were present on the external cell surface and persisted after removal of nerve terminal. Schwann cell, and postsynaptic plasma membrane. Thus, the antigens are contained in or connected to BL of the synaptic cleft. Details of staining patterns, differential susceptibility of antigens to proteolysis, and adsorption experiments showed that the antibodies define at least three different determinants that are present in synaptic but not extrasynaptic BL.
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PMID:Antibodies that bind specifically to synaptic sites on muscle fiber basal lamina. 9 19

Rotational diffusion of band 3 in the human erythrocyte membrane has been investigated using the technique of flash photolysis. Membranes are labeled with the triplet probe eosin isothiocyanate; most of the label is found to be associated with band 3. Rotation is measured by observing the decay of dichroism of flash-induced absorbance changes arising from the eosin probe. The results indicate that band 3 rotates about an axis normal to the plane of the membrane with a diffusion coefficient in the order of 1,000 sec-1. Removal of spectrin has no observable effect on the rotation of band 3 at pH 7.6. Essentially similar results are obtained with a different probe, iodoacetamidoeosin. Both eosin derivatives are strong inhibitors of anion transport. Illumination of eosin-labeled ghosts causes a rapid loss of acetylcholinesterase activity but this can be prevented by prior displacement of oxygen in the sample by argon.
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PMID:Rotational diffusion of band 3 in the red cell membrane: measurements using triplet probes. 9 46


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