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)

The rabbit appendix, a region of gut with well organized zones of lymphoid tissue, was examined with the glyoxylic acid histofluorescence technique for the localization of noradrenergic fibers, with high performance liquid chromatography with electrochemical detection (LCEC) for the quantitation of norepinephrine and serotonin, with Bielshowski and Giemsa stains for additional information about neural supply, and with acetylcholinesterase histochemistry for the localization of this hydrolytic enzyme. Fluorescent plexuses entered the serosal surface of the appendix associated with blood vessels, traveled longitudinally inside the muscularis interna, mainly in association with blood vessels but adjacent to enteric smooth muscle, and branched into long, linear, varicose plexuses that ran inward in a radial orientation towards the lumen in the internodular septa. As these fibers approached the interdomal regions near the epithelial surface, they passed through thymus-dependent cell zones, and arborized extensively throughout the interdomal region. A high density of varicosities was found in the subepithelial region where immunoglobulin-secreting plasma cells are found. These varicosities were sparse at 21 days of age, but were increased in number at 42 days of age. They were even further increased in number and density in adults. These fibers were further identified with a Bielshowski silver stain, and also demonstrated acetylcholinesterase activity. The noradrenergic varicosities in the interdomal regions of the adult rabbit appendix were closely associated with numerous yellow fluorescent cells of 25-40 microns diameter, which sometimes demonstrated fine varicose processes. The adult rabbit appendix contained a moderate concentration of norepinephrine (163.0 +/- 22.9 ng/g wet weight) and a very high concentration of serotonin (3981 +/- 283 ng/g wet weight). Levels in neonates were considerably lower, suggesting that the yellow fluorescent cells may contain serotonin. Acetylcholinesterase was associated with neural fibers and with non-neural regions of the lymph nodules and the domes, perhaps playing a protective role for these regions of the cellular immune system. The rabbit appendix is a well organized region of lymphoid tissue with specific zones of noradrenergic innervation and possible "paraneuronal" activity, with a readily accessible lumen for the isolation and collections of secretions. We propose this model as an excellent structure for further exploration of interactions between the nervous and immune systems.
 ...
PMID:Noradrenergic sympathetic innervation of lymphoid tissue in the rabbit appendix: further evidence for a link between the nervous and immune systems. 731 99

The release of vasoactive intestinal peptide (VIP) from the canine gut and its possible neural origin were studied using two agents, oxytocin and neostigmine, known to increase peripheral levels of VIP. Oxytocin and neostigmine increased the portal concentrations of VIP by threefold and sevenfold, respectively. A considerable portal/femoral vein gradient ranging from twofold in the basal state to sevenfold during stimulation with neostigmine indicated that the gut was the main source of circulating VIP. The contribution of the brain was minor, and that of the uterus was undetectable. Release of VIP occurred from the entire gut: After enterectomy, the residual gut (stomach, pancreas, and proximal duodenum) released spontaneously a large amount of VIP which masked the effect of oxytocin. Tetrodotoxin and hexamethonium, but not atropine, inhibited oxytocin-stimulted release of VIP by 80% and 60% respectively. This prompted the conclusion that the release of VIP was predominantly neurally mediated and that the chain of transmission involved a preganglionic cholinergic pathway. Hexamethonium strongly inhibited neostigmine-stimulated release of VIP. Atropine was even more potent in that it abolished the effect of neostigmine. The effect of atropine was attributed to a blockade of ganglionic muscarinic receptors, which are preferentially activated by cholinesterase inhibitors like neostigmine. The results of this study and those derived from electrical stimulation of the vagus nerve are consistent with the hypothesis that circulating VIP is released from intrinsic neurons of the gut under preganglionic cholinergic control.
 ...
PMID:Neural release of vasoactive intestinal peptide from the gut. 743 34

Extracts of rat tissues were subjected to ultracentrifugation on linear density gradients of sucrose (5-20%) and fractions of these gradients were analyzed for acetylcholinesterase (AChE) activity. Most of the AChE activity in extracts of vagus nerve was found to sediment at 10S. However, 16S AChE, previously thought to be confined to somatic motor nerves and skeletal muscle, was observed to accumulate rapidly at a nerve ligation. A search for this rapidly sedimenting form of AChE was carried out in tissues receiving vagal innervation. Significant amounts of 16S AChE were detected in the heart, especially in the right atrium, and in several regions of the gut. It was concluded that 16S AChE is distributed more widely than has previously been recognized.
 ...
PMID:Multiple molecular forms of acetylcholinesterase in rat vagus nerve, smooth muscle, and heart. 745 10

Radiation profoundly alters the contractile activity of the small intestine and colon. We hypothesized that some motor changes of the gut might be secondary to impaired neural input to smooth muscle or abnormal release of gut endocrine peptides. The density of products within peptidergic and cholinergic nerves and gut endocrine cells was estimated in six normal controls and six dogs who had received 1500 cGy in six equal fractions of 250 cGy. Choline acetyltransferase, acetylcholinesterase, vasoactive intestinal peptide (VIP), substance P, peptide YY (PYY), and motilin were measured in tissue specimens divided into mucosal-submucosal (MS) and muscularis externa (ME) layers. Tissue samples were obtained from the duodenum, jejunum, ileum, and proximal and distal colon. In addition, serum levels of motilin and PYY were determined before and during the administration of 1500 cGy in four separate dogs instrumented to record upper gut contractile activity. Intrinsic cholinergic activity as estimated by choline acetyltransferase activity was unchanged, while acetylcholinesterase activity increased in the MS layers of distal small bowel and colon. VIP was increased in the MS layers of jejunum and proximal colon as well as in the ME layers the jejunum and ileum. By contrast, substance P increased in the jejunal and proximal colonic MS layers and in the ME layers of the jejunum and ileum. Duodenal and jejunal motilin levels markedly decreased after radiation exposure, while serum motilin levels continued to cycle at a decreased peak level with migrating motor complexes. Colonic PYY remained unchanged but serum PYY levels decreased after irradiation. Increased neuronal synthesis and inhibition of neurotransmitter release are potential explanations for elevated tissue concentrations of VIP, substance P, and acetylcholinesterase. There appeared to be differences in the sensitivity of gut endocrine cells to irradiation. Changes in gut regulatory peptides and cholinergic enzyme activity occur with fractionated doses of abdominal irradiation, while the same schedule of irradiation produces striking changes in the canine small intestinal and colonic motor activity. It is therefore likely that alterations of contractile events may be produced by changes in gut neuroendocrine products.
 ...
PMID:Fractionated irradiation alters enteric neuroendocrine products. 754 59

The localization of nitric oxide synthase, the enzyme responsible for producing the short-acting messenger nitric oxide, has been determined in the digestive tract of the rat using histochemistry for reduced nicotinamide adenine dinucleotide phosphate-diaphorase activity, a specific marker for neuronal nitric oxide synthase. Positively stained neurons were found throughout the entire digestive tract from the esophagus to the rectum. Positive neuronal somata were very common in the myenteric ganglia. Dense positive fibers were distributed in internodal strands, the secondary plexus, the tertiary plexus, and were particularly abundant in the deep muscular plexus, while very few were observed in the submucosal ganglia. The density of these positive structures was higher in the small and large intestine than in the esophagus and stomach. The pattern of distribution suggested that some of these positive cells innervate gut muscles. Double-staining revealed that in these enteric neurons, nitric oxide synthase does not co-localize with acetylcholinesterase. Instead, vasoactive intestinal polypeptide almost always coexists with nitric oxide synthase in the myenteric plexus. Thus, nitric oxide and vasoactive intestinal polypeptide may be co-transmitters in a population of non-adrenergic, non-cholinergic neurons in the enteric nervous system.
 ...
PMID:Histochemical localization of nitric oxide synthase in rat enteric nervous system. 768 13

Between 1986 and 1991 773 infants were investigated by biopsy. 209 children suffered from a neuronal dysplasia of the submucous plexus (NID B). 64 of these 209 cases had concomitant Hirschsprung's disease with NID. The combination of Hirschsprung's disease with NID was established at biopsy not earlier than at 12 +/- 6 months of age. The classical form of an isolated aganglionosis had a median age at diagnosis of 4 +/- 2 months. The preconditions for a reliable diagnosis of NID are mucosal biopsies with submucosa taken 1, 3 and 9 cm above the pectinate line, the preparation of 15 microns thick serial sections, a acetylcholinesterase- and lactate-reaction and a systematic examination of all serial sections. Giant ganglia, which are 2-3 times as large as normal ganglia and having more than 7 LDH-positive nerve cells (10 +/- 3 nerve cells in the mean), are the most relevant parameters in the diagnosis of NID. They can be observed in infants as well as in adults. The NID proximal to aganglionosis is in principle not different from an isolated form of NID. Increase of acetylcholinesterase-activity in muscularis mucosae and lamina propria mucosae and a "hyperplasia" of the submucous plexus in early infancy disappears with advancing age and are very seldom observed at 2 years of age or in adulthood. NID B is the mildest form of a developmental abnormality of the autonomic nervous system, which shows in most cases a spontaneous normalization of gut motility.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:The neuropathological diagnosis of neuronal intestinal dysplasia (NID B). 785 82

Experiments were conducted to examine the dynamics of a sediment-associated pesticide azinphosmethyl (APM) using a sublethal benthic based trophic transfer model (meiobenthic copepods to juvenile fish). Two predominant pathways for contaminant transfer during feeding, prey ingestion and sediment ingestion, were examined to determine their relative contributions to APM transfer and subsequent effects on fish brain AChE inhibition. Experiments were conducted in 1993 and in 1994. Field collected benthic copepods were exposed to 14-C labeled APM, a potent acetylcholinesterase (AChE) inhibitor, in sediments for 96 h. APM burdens were measured in the copepods, and these contaminated copepods were fed to the juvenile fish predator Leiostomus xanthurus in uncomtaminated sediments. After gut clearance, fish were examined for brain AChE activity and APM residues in the liver, heart, gut, muscle, gill, and remains. Similar experiments were conducted in which meals of uncontaminated copepods were fed to spot in APM contaminated sediments, to determine the relative contribution of contaminated sediments to APM transfer. Copepods exposed to APM at a mean sediment concentration of 1223 ng/g dry weight accumulated APM at the level of 2.5 &mgr;g/g dry tissue. Brain AChE activity was significantly depressed (23%) in the 1993 fish fed one meal of contaminated copepods, however there was no significant decline in AChE activity in the fish tested during 1994. APM accumulation in fish feeding in contaminated sediments was generally greater than in fish feeding on contaminated prey. Significant accumulation was found in bodily remains, gills, gut, and muscle in fish that fed in contaminated sediments. No significant APM accumulation was found in fish fed the contaminated copepods.
 ...
PMID:Trophic Transfer of a Sediment-Associated Organophosphate Pesticide from Meiobenthos to Bottom Feeding Fish 866 21

The morphology of the intrinsic innervation of internal anal sphincter (IAS) in Hirschsprung's disease (HSCR) and allied disorders has not been clearly defined. At the time of IAS myectomy, specimens of the IAS were taken from four patients with HSCR, five patients with intestinal neuronal dysplasia (IND), five patients with IAS achalasia, and two patients with hypoganglionosis. Specimens also were taken from five normal controls. The specimens were examined using neural cell adhesion molecule (NCAM) immunohistochemistry, NADPH-diaphorase histochemistry, and acetylcholinesterase (AChE) histochemistry. The number of AChE-positive nerve fibers was markedly increased in the IAS of patients with HSCR, IND, and IAS achalasia compared with controls. NCAM and NADPH-diaphorase activity was absent or markedly reduced in the IAS of patients with HSCR, IND, and IAS achalasia. The IAS of patients with hypoganglionosis show markedly reduced NCAM and NADPH-diaphorase activity and occasional AChE-positive nerve fibers. These findings show that patients with HSCR, IND, hypoganglionosis, or IAS achalasia have abnormal innervation of the IAS and this may contribute to disturbances in gut motility in these conditions.
 ...
PMID:Abnormal internal anal sphincter innervation in patients with Hirschsprung's disease and allied disorders. 878 6

1. The cholinesterases play an important role in the innervation of organs. The ratio of solubilized to membrane-bound cholinesterase and the quantitative distributions of acetylcholinesterase and butyrylcholinesterase were measured in different segments of the gut of carp (Cyprinus carpio) connected with different types of nerve-muscle synapses in different parts of the alimentary tract. 2. The inhibition of acetylcholinesterase (EC 3.1.1.7.) by the herbicide paraquat and the insecticide metidathion was measured in different parts of the gut of carp. 3. Metidathion and paraquat significantly decreased the activity of acetylcholinesterase in different segments of the alimentary tract of common carp, in a concentration-dependent manner.
 ...
PMID:Quantitative distributions of different cholinesterases and inhibition of acetylcholinesterase by metidathion and paraquat in alimentary canal of common carp. 919 93

"Gut injury" and a corresponding impaired gut barrier function are thought to have a high impact on the development of multiple organ failure (MOF) in the critically ill. Mucosal lesions and increased intestinal permeability can provoke translocation of bacteria and endotoxins and initiate local and/or systemic immune-inflammatory response, bearing the risk of development of multiple organ failure. Enteral nutrition using the physiological pathway provides the intestinal mucosa with nutrients, which is thought to reduce bacterial translocation and septic complications. Considerable gastric reflux and delayed bowel motility are the principal problems of enteral nutrition. Therefore, in the early postoperative period at least a nasoduodenal or--jejunal feeding tube or feeding jejunostomy is required. The commonly used enteral formulas are well tolerated. So-called "immunonutrition" includes special formulas supplemented with immunemodulating substances like arginine, omega-3-fatty acids, ribonucleic acids and glutamine. Some beneficial effects of immune-enhancing diets have recently been reported for immune response, infectious complication rate, systemic inflammatory response syndrome (SIRS), multiple organ failure (MOF), antibiotic usage and length of hospital stay, especially in patients after trauma or surgery. However, the definite role is still unknown and indications have still to be defined. Enteral feeding should start with small volumes, the amount being gradually increased according to a patient's individual tolerance. Common problems are gastric reflux, diarrhoea and distension, but usage of a suitable formula, a gradual increase or reduction in the amount of enteral feeding and, additionally, parenteral nutrition can help to overcome such complications. Clinical examination of the enterally fed patient should be performed carefully. Standard nutritional monitoring of electrolytes, glucose, triglycerides, cholinesterase, albumin, differential blood count, urine-glucose and nitrogen retention to assess the catabolic state should be performed routinely. Although only little data from randomised trials are available, enteral nutrition has advantages and is cheaper than total parenteral nutrition. In the critically ill, the goal of enteral feeding is not coverage of total caloric requirements, but continuous administration of at least a small amount in order to prevent gut mucosa atrophy. Nutrition is an important aspect in critical care medicine, and enteral feeding should be attempted at least partially.
 ...
PMID:[Practical aspects of early enteral feeding]. 1052 15


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>