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)

Islets transplanted beneath the kidney capsule become reinnervated during the first 3-4 months after implantation by both afferent and efferent nerve fibers. To evaluate the importance of the implantation organ for this process, the present study compared both the degree and the types of nerve fibers reinnervating islets transplanted into the liver, kidney, and spleen. For this purpose, 150 syngeneic islets were grafted under the kidney capsule of C57BL/6 mice. In addition, the same animals were injected with 150 islets into the spleen or liver. All animals were killed 14 weeks after transplantation, after which the graft-bearing organs were processed for indirect immunofluorescence for neuropeptides and tyrosine hydroxylase (TH), and with acetyl cholinesterase (AchE) staining to visualize nerve fibers. Both afferent (containing substance P and/or calcitonin gene-related peptide) and parasympathetic (containing vasoactive intestinal peptide or AchE) nerve fibers were absent from islets implanted into the spleen; an occasional CGRP fiber was seen in islets implanted into the liver; and all these fibers were regularly seen in islets implanted beneath the renal capsule. The islets implanted into the liver or spleen contained a dense network of sympathetic (containing neuropeptide Y and TH) nerve fibers that was often more dense than in the islet grafts under the kidney capsule. One-fifth of islets implanted into the liver were, however, completely devoid of demonstrable nerve fibers. In conclusion, there are marked differences with regard to the pattern of reinnervation of islets transplanted to different implantation sites.
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PMID:Reinnervation of transplanted pancreatic islets. A comparison among islets implanted into the kidney, spleen, and liver. 768 93

Behavioural and neurochemical analyses were carried out to investigate the relationship between the antinociceptive activity of porcine calcitonin (pCT) and central cholinergic system in mice and rats. Behavioural studies revealed that the antinociceptive activity of pCT encapsulated in sulphatide-containing liposomes injected intravenously into mice was significantly inhibited by atropine sulphate, but not by atropine methylnitrate, and potentiated by physostigmine, but not by neostigmine. Neurochemical studies using rat brain synaptosomes showed that pCT stimulated synaptosomal sodium-dependent high-affinity choline uptake, which was found to be closely associated with acetylcholine (ACh) synthesis (50-60%). This effect was concentration-dependent. In addition, pCT elicited a biphasic effect on ACh release from synaptosomes with an initial brief period of stimulation and subsequent prolonged inhibition. This stimulation was not affected by atropine sulphate, but markedly reduced by incubation in the presence of diltiazem or in a calcium-free medium, indicating that the modulation of ACh release by the peptide may be mediated by calcium fluxes across the synaptosomal membrane independent of cholinergic receptor activation. However, pCT does not affect the activity of synaptosomal acetylcholinesterase. Therefore, the behavioural study in vivo with the neurochemical analysis in vitro suggests that the central cholinergic system may be involved in the antinociceptive activity of calcitonin.
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PMID:Antinociceptive activity of calcitonin and central cholinergic system: behavioural and neurochemical analyses. 778 3

Systemic administration of murine monoclonal acetylcholinesterase antibodies to rats has been shown to cause selective degeneration of sympathetic preganglionic neurons. In the present study rats were subjected to a single i.v. injection of these acetylcholinesterase antibodies, or to normal IgG or saline for control. Exophthalmos, piloerection and eyelid-drooping (ptosis) were observed within 1 h after administration of the antibodies. Rats were killed at different time-points after antibody administration, and the adrenal glands were analysed by means of indirect immunohistochemistry and in situ hybridization histochemistry. As soon as 3 h after the antibody treatment, a marked increase in the number of chromaffin cells expressing mRNA encoding, respectively, enkephalin, calcitonin gene-related peptide, galanin, neurotensin and substance P was seen. At 12 h the peptide mRNA levels were still elevated and there was a concomitant increase in the number of peptide-immunoreactive cells. All peptide levels remained high for at least 48 h; however, 77 days after the antibody treatment only enkephalin-immunoreactive cells could be encountered. A disappearance of acetylcholinesterase- and enkephalin-immunoreactive cells could be encountered. A disappearance of acetylcholinesterase- and enkephalin-positive fibers was already seen 3 h after the antibody treatment, and after 24 h no fibers were encountered. In contrast, up until 48 h there was no apparent change in the number or intensity of immunofluorescent fibers expressing calcitonin gene-related peptide, galanin, neurotensin or substance P. However, 77 days after the antibody treatment the number of calcitonin gene-related peptide- and substance P-immunoreactive fibers was increased as compared to controls. In addition, reappearance of acetylcholinesterase- and enkephalin-immunoreactive fibers was seen 77 days after antibody administration, although their number was still low as compared to controls. Double-labeling immunohistochemistry revealed that the chromaffin cells expressing peptides after the antibody treatment preferentially were adrenaline storing cells (noradrenaline-negative). The majority of these cells expressed only one peptide. Both surgical transection of the splanchnic nerve as well as treatment with acetylcholine receptor antagonists mimicked the effects seen after the acetylcholinesterase-antibody treatment, although changes were less pronounced. The present results show that interruption of splanchnic transmission induces fast, marked, and selective increases in peptide expression in rat adrenal chromaffin cells.
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PMID:Immunologically induced sympathectomy of preganglionic nerves by antibodies against acetylcholinesterase: increased levels of peptides and their messenger RNAs in rat adrenal chromaffin cells. 781 1

The innervation and vasomotor responses to several vasoactive agents of guinea pig epicardial coronary veins were investigated by means of immunohistochemical, histochemical, ultrastructural and in vitro pharmacological techniques. The use of an antiserum to the general neuronal marker protein gene product 9.5 revealed that coronary veins are supplied by a network of fine varicose nerve fibres in the adventitia. The majority of the nerve fibres possessed neuropeptide Y (NPY) and tyrosine hydroxylase immunoreactivity. Only a few nerve fibres displayed substance P, neuropeptide K (NK) and calcitonin gene-related peptide (CGRP) immunoreactivity. In double stained preparations substance P immunoreactivity was co-localized with NK and CGRP in the same nerve fibres. Nerve fibres containing vasoactive intestinal peptide (VIP) immunoreactivity or acetylcholinesterase activity were not detected. Endothelin immunoreactivity was also found in the vein endothelial cells. Ultrastructural studies revealed the presence of axon varicosities at the adventitial-medial border. In vitro pharmacological studies showed that endothelin-1 and -2 elicited a significant contractile response of epicardial vein segments. Noradrenaline, NPY, serotonin and uridine 5'-triphosphate induced only a relatively weak contractile response in the vein segments. Although vasodilatory responses were difficult to examine in these preparations, it was found that substance P, CGRP and VIP elicited a relaxation of the vein segments. These results indicate that guinea pig epicardial coronary veins are innervated by several nerve populations, however, the control of vasomotor tone of coronary veins appears to be predominantly regulated by 'non-neuronal' vasoactive agents such as endothelin and 5-HT.
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PMID:The innervation of guinea pig epicardial coronary veins: immunohistochemistry, ultrastructure and vasomotility. 791 47

Footpads of normal adult mice are innervated by sympathetic and sensory fibers. The sympathetic fibers associated with sweat glands contain acetylcholinesterase and immunoreactivity for vasoactive intestinal peptide. Although catecholamine histofluorescence is absent, the gland innervation exhibits immunoreactivity for tyrosine hydroxylase. A distinct population of sympathetic fibers, which possess catecholamines and neuropeptide Y as well as tyrosinehydroxylase immunoreactivity, innervates blood vessels. Sensory fibers containing immunoreactivity for substance P and calcitonin gene-related peptide course beneath the epidermis and some form endings in it. Treatment of neonatal mice with the adrenergic neurotoxin, 6-hydroxydopamine, results in loss of sympathetic innervation of sweat glands and blood vessels, permits growth of sensory axons into sweat glands, but does not alter the peptidergic sensory innervation of the dermis and epidermis. Three mouse mutations, Tabby (Ta), crinkled (cr), and downless (dl), disrupt the interactions between the mesenchyme and epidermis that are required for normal development of specific epidermal derivatives, including sweat glands. The sympathetic innervation of blood vessels and sensory innervation of footpad skin of the three mutant mice that lack sweat glands is indistinguishable from normal. The sympathetic fibers that normally innervate sweat glands, however, are not present. These results indicate that in the absence of their normal target, the sympathetic fibers that innervate sweat glands are lacking. Furthermore, they suggest that, although sensory fibers may sprout into sympathetic targets in the footpad, the domains occupied by sensory fibers are not normally accessible to sympathetic axons.
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PMID:Innervation of footpads of normal and mutant mice lacking sweat glands. 798 47

Heart rate is regulated by the autonomic nervous system but little is known about the pattern of innervation of the pacemaker in the sinoatrial node, or the subpopulations of nerves involved. Therefore in this study the pacemaker was located using electrophysiological methods and the pattern of innervation established by cholinesterase staining. In subsequent experiments, subpopulations of sympathetic, sensory and parasympathetic nerves were identified. Sympathetic nerves were labelled by glyoxylic acid-induced catecholamine fluorescence or an antiserum raised against tyrosine hydroxylase (TH). These experiments showed that the entire sinoatrial node was densely innervated by sympathetic axons, the majority of which were immunoreactive for neuropeptide Y (NPY). There were a few axons which were only immunoreactive for TH. Sensory nerves which were immunoreactive for both substance P (SP) and calcitonin gene-related peptide (CGRP) were also found throughout the sinoatrial node. In the absence of a selective marker for parasympathetic neurons, hearts were extrinsically denervated by placing them in organotypic culture to allow degeneration of extrinsic axons. In this way intrinsic parasympathetic neurons could be characterised. These experiments revealed several distinct populations of parasympathetic nerves which innervated only a small, discrete part of the sinoatrial node. These populations were immunoreactive for NPY, somatostatin (SOM) or vasoactive intestinal peptide (VIP) alone, or SOM combined with NPY, SOM with dynorphin B, and SOM with SP. These results highlight a remarkable difference in the pattern of innervation of the sinoatrial node by the sympathetic and parasympathetic nervous systems. Furthermore the presence of several distinct populations of autonomic cardiac neurons indicates a further complexity in neuronal regulation of heart rate.
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PMID:Innervation of the pacemaker in guinea-pig sinoatrial node. 801 78

A novel method to selectively lesion preganglionic sympathetic neurones has been combined with immunohistochemistry to study the expression of peptides in the rat superior cervical ganglion (SCG). Thus, systemic administration of monoclonal antibodies against acetylcholinesterase (AChE) caused a marked reduction in the number of enkephalin (ENK)-positive fibres and a total disappearance of fibres immunoreactive for calcitonin gene-related peptide (CGRP) and AChE in the SCG. A marked increase in the number of galanin/galanin message-associated peptide (GAL/GMAP)-immunoreactive cell bodies was also observed. The present results indicate that probably all CGRP and most ENK containing fibres in the rat SCG are of preganglionic origin and that peptides not normally expressed in SCG neurones, e.g. GAL and GMAP, can be upregulated after deafferentation.
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PMID:Effects of preganglionic sympathectomy on peptides in the rat superior cervical ganglion. 806 Dec 94

In the rat, systemic administration of murine monoclonal antibodies against acetylcholinesterase caused rapid piloerection and ptosis (within 30-60 min after the injection). Using indirect immunohistochemistry the effect of these antibodies on peptides and enzyme expression was studied in the rat adrenal gland. Four days after antibody administration a total disappearance of acetylcholinesterase-immunoreactive fibers was observed. However, groups of acetylcholinesterase-immunoreactive chromaffin cells and intramedullary ganglion cells, both cell types showing acetylcholinesterase immunoreactivity also in the control adrenal medulla, expressed increased immunoreactivity. Analysis revealed that the acetylcholinesterase-immunoreactive chromaffin cell groups lacked phenylethanolamine-N-methyltransferase staining both in controls and treated rats. Antibody administration also affected levels of several peptides present in nerve fibers and chromaffin cells. Thus, the number of cells expressing enkephalin, calcitonin gene-related peptide and galanin was dramatically increased compared to the very few cells observed containing these three peptides in the normal gland. The majority of cells expressing enkephalin after antibody treatment also showed phenylethanolamine-N-methyltransferase immunoreactivity. In contrast, the few chromaffin cells expressing strong enkephalin-like immunoreactivity in controls were phenylethanolamine-N-methyltransferase negative. The sparse networks of calcitonin gene-related peptide- and galanin-positive fibers found in control adrenals were unchanged after the antibody treatment. However, the dense network of enkephalin varicose fibers totally disappeared after the antibody injection. A few substance P- and somatostatin-immunoreactive cells, not present in the normal gland, appeared after administration of the antibodies, whereas no changes were encountered with regard to immunoreactive nerve fibers. No clear differences between normal and treated animals could be observed in chromaffin cells with regard to immunoreactivity for neuropeptide Y or any of the four catecholamine-synthesizing enzymes, tyrosine hydroxylase, aromatic 1-amino acid decarboxylase, dopamine beta-hydroxylase or phenylethanolamine-N-methyltransferase. The present findings demonstrating a disappearance of acetylcholinesterase- and enkephalin-immunoreactive nerve fibers in the adrenal gland after intravenous injection of acetylcholinesterase antibodies support earlier reports showing that these antibodies cause degeneration of preganglionic fibers, and that neuronal decentralization of the adrenal gland induces marked increases in the levels of several peptides in chromaffin cells.
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PMID:Effects of antibodies against acetylcholinesterase on the expression of peptides and catecholamine synthesizing enzymes in the rat adrenal gland. 810 82

Inclusion of salmon calcitonin in the culture medium of rat ventral prostate explants diminished l-tartarate-sensitive acid phosphatase activity in the tissues with a concomitant increment of the enzyme activity in the medium. The effect of the hormone was dose-dependent for a dose range of 10(-12)-10(-6) M. Acid phosphatase activity in prostate explants decreased from 38.6 +/- 3.5 to 20.5 +/- 2.8, whereas it increased from 0.60 +/- 0.15 to 2.80 +/- 0.40 nmol p-nitrophenol liberated/mg protein/30 min in the culture medium. Tissues exposed to 10(-6) M salmon calcitonin had higher acetylcholinesterase activity (8.8 +/- 0.7) than non-exposed ones (6.2 +/- 0.5 mumol substrate hydrolyzed/g tissue/min). These results suggest that locally produced calcitonin causes a release for prostatic acid phosphatase from prostate tissues possibly through its interaction with the cholinergic system.
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PMID:Calcitonin releases acid phosphatase from rat ventral prostate explants. 810 34

To investigate the influence of the cholinergic system on the modulation of the circulating levels of calcitonin gene-related peptide (CGRP) under basal conditions in normal man, the effects of an acetylcholinesterase inhibitor, pyridostigmine bromide, and a muscarinic receptor blocker, pirenzepine, were studied in 16 normal subjects (8 females and 8 males). Pyridostigmine (120 mg, orally) induced a significant (P < 0.01) rise in basal plasma CGRP, while it reduced systolic and diastolic blood pressure. In all subjects, pirenzepine (0.6 mg/kg, i.v. bolus) was unable to modify the basal CGRP level. In conclusion, a pharmacologically induced enhancement of cholinergic tone resulted in an increase in CGRP, whereas muscarinic receptor blockade had no effect on CGRP levels or blood pressure. Therefore, the cholinergic system seems to be involved in the control of CGRP release in man, acting as a positive modulator. However, the available data do not indicate that there is a tonic cholinergic tone responsible for CGRP secretion under physiological conditions.
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PMID:Evidence that enhancement of cholinergic tone increases basal plasma levels of calcitonin gene-related peptide in normal man. 812 54


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