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)

Behavioral training of guinea pigs by conventional methods, such as used for rats and mice, appears difficult. Hence, only a few behavioral experiments with guinea pigs have been described in the literature. An active avoidance technique in an automated two-way shuttlebox is described using sound as a conditioned (CS) and a tactile stimulus (a stream of air ruffling their fur) as an unconditioned (UCS) stimulus. Acquisition is fairly rapid and reproducible. Doses of physostigmine that caused moderate blood acetylcholinesterase inhibition induced dose-dependent performance decrements. These decrements were counteracted by a sign-free dose of scopolamine.
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PMID:Active avoidance behavior in guinea pigs: effects of physostigmine and scopolamine. 163 Nov 81

A subacute toxicity study of propiverine hydrochloride (P-4), a new anti-pollakiuria agent, was carried out using male and female Wistar rats. P-4 was orally administered to rats at dose levels of 2, 10, 50 and 150 mg/kg/day for 13 weeks, followed by 5 weeks recovery period. The results obtained are as follows: 1. In the general conditions, transient salivation was observed immediately after administration and blotted fur at lower abdomen was noted in rats given 50 mg/kg/day or more. There were no deaths related to P-4. 2. Body weight gain was depressed in males given 50 mg/kg/day or more and females given 150 mg/kg/day. No significant changes in food consumption were observed. Water consumption increased in the groups of 50 mg/kg/day or more. 3. Urinalysis revealed an increase of urine volume, decreases of osmotic pressure, protein and urobilinogen, and a slight increase in excretion of electrolyte in rats given 50 mg/kg/day or more. 4. Hematological examinations revealed slight changes such as an increase in erythrocyte count and a shortening of APTT in rats given 150 mg/kg/day. 5. Serum biochemical examinations showed a decrease in triglyceride and increases in gamma-GTP and AlP activities, and urea nitrogen in males given 50 mg/kg/day or more and females given 150 mg/kg/day. Additionally, decreases in total and free cholesterol, and phospholipid for males and an increase of total cholesterol and a decrease of cholinesterase activity for females were detected. 6. At autopsy, atrophy of thymus and spleen was observed in rats given 50 mg/kg/day or more, but without histopathological correlation. Histopathological examinations revealed hypertrophy and fatty degeneration of hepatocytes, which were accompanied with increases of absolute and/or relative liver weight, in males given 50 mg/kg/day or more and females given 150 mg/kg/day. Electron-microscopy showed proliferation of smooth endoplasmic reticulum in the same groups. In the kidney, eosinophilic and intranuclear inclusions in the tubular epithelium were detected, in which cytoplasm there were no toxic injuries, in males given 10 mg/kg/day or more and females given 50 mg/kg/day or more. 7. After 5 weeks recovery period, above-mentioned changes were generally disappeared, suggesting that these were reversible. 8. The non-effective dose levels and the toxic dose levels of P-4 were estimated to be 2 mg/kg/day for males and 10 mg/kg/day for females, and 50 mg/kg/day for males and 150 mg/kg/day for females, respectively.
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PMID:[Thirteen-week oral toxicity study of propiverine hydrochloride in rats]. 260 52

This experiment was designed to study the effect of ambient temperature (Ta) on the thermoregulatory response after the injection of the acetylcholinesterase blocking agent, physostigmine, into the preoptic/anterior hypothalamic area (POAH) of the rat. Three doses of physostigmine (3.0, 30.0 and 60.0 micrograms) were injected in a volume of 1.0 microliter in the preoptic/anterior hypothalamic area of unrestrained rats at three different ambient temperatures (15, 25 and 35 degrees C). Brain temperature (Tbr) and gross changes in behavior were monitored continuously throughout the duration of each experiment. Physostigmine induced hypothermia at ambient temperatures of 15 and 25 degrees C but not at 35 degrees C. Immediately prior to and during the hypothermic response the animals displayed behavioral reflexes such as fur licking and a sprawled posture which presumably enhanced heat loss. Generally, soon after the peak of the hypothermic response (approximately 30 min), the rats displayed heat-conserving behavior (huddled position, piloerection of the fur). These data indicate that the activity of cholinergic synapses within the preoptic/anterior hypothalamic area increases with decreasing ambient temperature. The behavioral observations suggest some role for the cholinergic system in the activation of heat-dissipating responses in the rat.
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PMID:Effect of ambient temperature on thermoregulation in rats following preoptic/anterior hypothalamic injection of physostigmine. 406 23

The sparse-fur (spf) mutant mouse has an X-linked deficiency of hepatic ornithine transcarbamylase (OTC) and develops hyperammonemia in the postnatal period similar to that seen in human patients. We studied the effect of congenital hyperammonemia on the development of cerebral cholinergic parameters such as choline acetyltransferase (ChAT), acetylcholinesterase (AChE) and high-affinity choline uptake (HACU) in spf mice. The serum ammonia levels of spf mutant mice were significantly elevated after weaning compared with control animals. ChAT activity levels started decreasing in mutant spf mice from the age of 30 days (i.e., immediately after weaning); it reached significantly lower levels in the adult animals. HACU was consistently lower (P < .01) in spf/Y mice compared with controls up to the adult stage. However, there were no marked changes in the activity of AChE between control and hyperammonemic spf mice. The levels of beta-NGF, which is essential for cholinergic differentiation and function, were significantly lower in different brain regions of adult mutant mice compared with normal controls. A treatment of spf/spf breeding females with acetyl-L-carnitine, at a dose of 1.5 mM in drinking water, starting from day 1 of conception, resulted in a significant restoration of ChAT activity levels in some brain regions of the spf/Y offspring. The beta-NGF levels were also significantly elevated after supplementation with ALCAR in mutant mice compared with untreated mutant mice. These data are suggestive of a neurotrophic property of ALCAR during cholinergic deficiency caused by congenital hyperammonemia.
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PMID:Developmental deficiency of the cholinergic system in congenitally hyperammonemic spf mice: effect of acetyl-L-carnitine. 761 28

Congenital ornithine transcarbamylase (OTC) deficiency in humans is associated with seizures and mental retardation. As part of a series of studies to delineate the neurochemical features of OTC deficiency, activities of choline acetyltransferase (ChAT) and acetylcholinesterase (AChE), respectively, were measured in brain regions of the congenitally hyperammonemic sparse-fur (spf) mouse, a mutant with an X-linked inherited defect of OTC. ChAT activities were reduced by 63% (P < 0.01) in cerebral cortex of spf mice compared with CD-1/Y controls. Activities of the GABA nerve terminal marker enzyme, glutamic acid decarboxylase, on the other hand, were within normal limits. Using an immunohistochemical technique with a monoclonal antibody to ChAT, a significant loss of ChAT-positive neurons was observed throughout the cerebral cortex, septal area and diagonal band of spf mice. These results suggest that a loss of forebrain cholinergic neurons is a feature of congenital OTC deficiency in these mutants. Possible pathogenetic mechanisms responsible for the cholinergic neuronal loss in congenital OTC deficiency include neurotoxic effects of ammonia and accumulation of quinolinic acid.
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PMID:Evidence for cholinergic neuronal loss in brain in congenital ornithine transcarbamylase deficiency. 781 42

Evidence suggests that proenkephalin and members of the chromogranin/secretogranin family of proteins are prohormone precursors, giving rise to a variety of peptides with biologic activity. However, the specific proteases responsible for cleaving these proteins in vivo have not been fully established. Several candidate proteases have been described, some of which have been shown to cleave these proteins in vitro. Proteolytic processing of the chromogranins may be particularly complex, occurring in specific tissue-dependent patterns. To account for this level of complexity several protease systems may be operative, either alone or in concert, both within the neurosecretory granule and in the extracellular space. Specific proteases which are available within neurosecretory cells or in the local extracellular environment, and which may cleave these prohormones include PC1 and PC2 (recently described members of the Kex2/furin family of endoproteases), as well as kallikrein, acetylcholinesterase, and, more recently, the plasminogen/plasmin protease system. The potential role of these specific proteases in the processing of proenkephalin and the chromogranins is discussed, in particular, in the context of possible processing clues available from recent analysis of cDNA and genomic intron/exon structure.
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PMID:Processing of chromaffin granule proteins: a profusion of proteases? 845 72

The parahippocampal area is a cortical region of the avian dorsomedial telencephalon. In the chicken embryo, it contains discrete clusters of cadherin-7-positive cells, which are embedded in a cadherin-7-negative matrix. In the present work, the development and spatial distribution of these clusters is studied in whole-mount specimens. The clusters form a complex, coherent pattern of patches of variable size, spacing, and staining intensity. The pattern is especially prominent and regularly spaced in the rostral part of the caudolateral parahippocampal area. Here, it consists of stripes and connecting bridges with an average periodicity of approximately 0.3 mm. This pattern vaguely resembles some animal fur patterns and the ocular dominance domain of the mammalian visual cortex. The cadherin-7-positive patches also differ from their surrounding area by their cytoarchitecture and their increased acetylcholinesterase activity, suggesting that they represent functionally specialized subregions within the parahippocampal area. During development, the patchiness is first observed between 9 and 10 days of incubation and gradually becomes more prominent until 15 days of incubation. Our results indicate that the patchy organization of cortical gray matter on a small scale of periodicity (below 1 mm), which is well studied in the mammalian neocortex, is also found in the avian telencephalon.
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PMID:Small-scale pattern formation in a cortical area of the embryonic chicken telencephalon. 1250 67

Children can be exposed to pesticides from numerous residential sources such as carpet, house dust, toys and clothing from treated homes, and flea control remedies on pets. In the present studies, 48 pet dogs (24 in each of two studies) of different breeds and weights were treated with over-the-counter flea collars containing chlorpyrifos (CP), an organophosphorus insecticide. Transferable insecticide residues were quantified on cotton gloves used to rub the dogs for 5 min and on cotton tee shirts worn by a child (Study 2 only). First morning urine samples were also obtained from adults and children in both studies for metabolite (3,5,6-trichloro-2-pyridinol) quantification. Blood samples were obtained from treated dogs in Study 1 and plasma cholinesterase (ChE) activity was monitored. Transferable residues on gloves for all compounds were highest near the neck of the dogs and were lowest in areas most distant from the neck. Rubbing samples (over the collar) at two weeks post-collar application contained 447+/-57 microg CP/glove while samples from the fur of the back contained 8+/-2 microg CP/glove. In Study 2, cotton tee shirts worn by children at 15 days post-collar application for 4 h showed CP levels of 134+/-66 ng/g shirt. There were significant differences between adults and children in the levels of urinary metabolites with children generally having higher urinary levels of metabolites than adults (grand mean+/-SE; 11.6+/-1.1 and 7.9+/-0.74 ng/mg creatinine for children and adults, respectively, compared to 9.4+/-0.8 and 6.9+/-0.5 ng/mg creatinine before collar placement). Therefore, there was little evidence that the use of this flea collar contributed to enhanced CP exposure of either children or adults.
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PMID:Assessing transferable residues from intermittent exposure to flea control collars containing the organophosphate insecticide chlorpyrifos. 1739 89

Fleas are a persistent problem for pets that require implementation of control measures. Consequently, pesticide use by homeowners for flea control is common and may increase pesticide exposure for adults and children. Fifty-five pet dogs (23 in study 1; 22 in study 2) of different breeds and weights were treated with over-the-counter flea collars containing tetrachlorvinphos (TCVP). During study 1, fur of treated dogs was monitored for transferable TCVP residues using cotton gloves to pet the dogs during 5-min rubbings post-collar application. Plasma cholinesterase (ChE) activity was also measured in treated dogs. Average amounts of TCVP transferred from the fur of the neck (rubbing over the collar) and from the back to gloves at 3 days post-collar application were 23,700+/-2100 and 260+/-50 microg/glove, respectively. No inhibition of plasma ChE was observed. During study 2, transferable TCVP residues to cotton gloves were monitored during 5-min rubbings post-collar application. Transferable residues were also monitored on cotton tee shirts worn by children and in the first morning urine samples obtained from adults and children. Average amounts of TCVP transferred to gloves at 5 days post-collar application from the neck (over the collar) and from the back were 22,400+/-2900 and 80+/-20 microg/glove, respectively. Tee shirts worn by children on days 7-11 contained 1.8+/-0.8 microg TCVP/g shirt. No significant differences were observed between adults and children in urinary 2,4,5-trichloromandelic acid (TCMA) levels; however, all TCMA residues (adults and children) were significantly greater than pretreatment concentrations (alpha=0.05). The lack of ChE inhibition in dogs and the low acute toxicity level of TCVP (rat oral LD(50) of 4-5 g/kg) strongly suggest that TCVP is rapidly detoxified and excreted and therefore poses a very low toxicological risk, despite these high residues.
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PMID:Assessing intermittent pesticide exposure from flea control collars containing the organophosphorus insecticide tetrachlorvinphos. 1816 6

Fleas, ticks, and mites are a major problem in many areas of the country for pet owners, and one treatment option involves the use of dips that contain pesticides. In the present study, dogs were dipped with a commercial phosmet (Imidan(R)) flea dip using the recommended guidelines for four consecutive treatments to determine the residues available for transfer to humans from the fur of the dogs. Twenty-four dogs of various breeds and weights were dipped, and each animal's fur was sampled with cotton gloves by petting for 5 minutes in a 10'' x 4'' area along the upper back before dipping and at 4 hours, and 1, 3, 7, and 14 days after dipping. Over the 4 dippings the 4-hour samples had a geometric mean of 2653 mug, and the 1-, 3-, 7-, and 14- day samples had geometric means of 877, 316, 84, and 20 mug, respectively. The samples ranged (in mug) from 80 to 16,794 at 4 hours, 44 to 7028 at 1 day, 1 to 4897 at 3 days, 1 to 2691 at 7 days, and 0.3 to 835 at 14 days. The residues removed by the petting did increase with the subsequent dips, but this was probably due to handler experience. The increase is not attributed to accumulation since there was less than 2% of transferable residue on the dog at 14 days post application. There was no significant inhibition of the plasma cholinesterase in the dogs over the study, suggesting that there was either a very low level of dermal absorption of phosmet or there was rapid detoxication (supported by EPA R 825170-01-0).
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PMID:Effects of topical phosmet on fur residue and cholinesterase activity of dogs. 2002 Oct 25


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