Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0014848 (achalasia)
 2,804 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The abnormal function of the lower oesophageal sphincter in achalasia is likely to be due to impaired nonadrenergic, noncholinergic (NANC) inhibitory input. Since recent studies in animals suggest that nitric oxide (NO) is implicated physiologically in the inhibitory responses of the lower oesophageal sphincter, we have investigated whether the synthesis of NO is altered in the gastro-oesophageal junction of patients with achalasia. NO synthase activity was investigated in samples of tissue from the gastro-oesophageal junction obtained during surgery in eight patients with typical achalasia and six non-achalasic controls who underwent oesophagectomy for reasons other than sphincter dysfunction. The NO synthase activity was determined by the transformation of 14C-L-arginine into 14C-L-citrulline in tissue homogenates. In addition, immunohistochemical staining of the tissues was performed using a polyclonal antibody raised against a peptide sequence of rat brain NO synthase. Furthermore, the relaxant response to an exogenous NO donor (sodium nitroprusside, SNP) was measured in vitro in muscle strips obtained from two patients with achalasia and in two non-achalasic controls. NO synthase activity was detected in each of the samples obtained from six control patients (0.59 +/- 0.21 pmol mg-1 min-1; mean +/- SE). By contrast, none of the samples obtained from the eight patients with achalasia had any detectable NO synthase activity. Immunohistochemical studies confirmed the presence of NO synthase in the myenteric plexus of the gastro-oesophageal junction of control patients and its absence in achalasia. SNP relaxed muscle strips precontracted with bethanechol in both control samples and those from patients with achalasia.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Patients with achalasia lack nitric oxide synthase in the gastro-oesophageal junction. 750 98

Nitric oxide (NO) is a neurotransmitter and neuromodulator in the central nervous system, but this small labile substance also seems to serve as a peripheral neurotransmitter. Abundant evidence is now available that NO, synthesized from L-arginine by NO synthase (NOS), is a nonadrenergic noncholinergic relaxant transmitter of gastrointestinal smooth muscle. Electrically induced nonadrenergic noncholinergic relaxations are antagonized by NOS inhibitors in vitro and in vivo. In a bioassay superfusion system, the release of a substance with the pharmacological characteristics of NO from a gastrointestinal smooth muscle preparation was detected; also, indirect measurements (e.g. of the NO metabolite nitrite or of the co-product of its synthesis L-citrulline) suggest NO release. Immunohistochemistry with antibodies raised against the neuronal NOS showed immunoreactivity in cell bodies of neurones in the myenteric plexus and in nerve fibres in the muscular layer. These data suggest that nerve endings, innervating smooth muscle, are able to release NO that will penetrate the cells to induce relaxation (i.e. nitrergic neurotransmission). It is unlikely that NO as such is stored and it is generally accepted that it is synthesized on demand when the nerve endings are excited, although the possibility of the release of a NO-containing molecule protecting it from degradation in the junction has been proposed. Other sources than neurones (interstitial cells, smooth muscle cells) for the NO involved in nonadrenergic noncholinergic inhibitory transmission have also been proposed. Using NADPH diaphorase as a marker for neuronal NOS, deficiency of the nitrergic innervation has been shown in isolated tissue from patients with infantile hypertrophic pyloric stenosis, achalasia and Hirschsprung's disease, suggesting that a lack of NO release might be involved in these disorders. Evidence in favour of nitrergic neurotransmission to smooth muscle has also been obtained in the respiratory and lower urinary tract, the corpora cavernosa and some blood vessels.
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PMID:Nitric oxide in the peripheral nervous system. 754 28

The digestive system is one of the major sources of nitric oxide, which, due to its smooth muscle-relaxing and vasodilating properties, appears to play a key role in the regulation of gastrointestinal motility, mucosal blood flow and gastroprotection. In addition nitric oxide takes part in the control of pancreatic secretion and liver functions. Recent studies suggest that the substance may be involved in the pathogenesis of achalasia, toxic megacolon, Hirschsprung's disease and portal hypertension.
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PMID:Nitric oxide: an ubiquitous actor in the gastrointestinal tract. 820 Jan 22

Identification of so called endothelium derived relaxing factor, EDRF, as nitric oxide, ON, produced in situ in digestive tract, as well as in many other organs, offers the possibility of pharmacologic control blocking or stimulating its production in situ. Theoretically, conditions like achalasia, cell injury by endotoxins, altered visceral arterial flow, hyperdynamic circulatory state in decompensated cirrhosis, protein synthesis and glomerular filtration in ascites, will be amenable of better treatment. This gas is considered as labile humoral-like messenger, mediator or a regulator of cell function in a number of physiological are promising. By now most of the information available comes from animal studies.
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PMID:[Nitric oxide in gastroenterology]. 852 12

Dysphagia is related to the impairment of food passage from the mouth to the stomach. Globus pharyngis implies the frequent and often painful sensation of a lump in the throat that usually does not interfere with swallowing and may even be relieved by food intake. The diagnosis is based upon a careful history, clinical examination, endoscopy, dynamic imaging (videofluoroscopy, cinematography, videosonography) and electrophysiologic procedures (including pharyngoesophageal manometry, electromyography and pH determinations). Structural lesions of the cervical spine such as diffuse idiopathic skeletal hyperostosis are rare causes of dysphagia. Dysphagia following anterior cervical fusion as well as globus and dysphonia due to dysfunction of the vertebral joints are more likely. Symptoms with swallowing fluids indicate a neurogenic origin. Dyscoordinated swallowing, nasal reflux, dysphonia or general weakness may also occur. Chronic aspiration with respiratory compromize is the main consequence in a variety of neurological disorders as well as in cases of postsurgical dysphagia. Relaxation of the upper esophageal sphincter indicates coordinated muscle movement between the pharynx and esophagus. Dysfunction of the pharyngoesophageal segment may lead to cricopharyngeal achalasia. A dyskinetic sphincter commonly represents an extrapharyngeal cause: i.e., disease associated with gastroesophageal reflux. Disorders of the esophageal phase of deglutition can produce retrosternal pain, heartburn, regurgitation and vomiting, as well as laryngeal and respiratory signs. Esophageal motility disorders include lower achalasia, tumors, peptic strictures, inflammatory diseases, drug-induced ulcers, rings and webs. Motility disorders present with aperistaltic, spontaneous contractions, diffuse esophagospasm, or a hypermotile esophagus. Gastroesophageal reflux with esophagitis must always be excluded, especially in patients with a globus sensation. The multiple features of the appearance of the symptoms of dysphagia and globus makes multidisciplinary approach necessary in order to establish a diagnosis and begin effective treatment.
HNO 1998 Aug
PMID:[Deglutition disorders]. 977 28

The normal regulation of oesophageal peristalsis is complex. Nitric oxide-containing inhibitory neurons and cholinergic excitatory nerve fibres play the key roles. In the so-called primary oesophageal motility disorders, the coordination of oesophageal contractions and lower oesophageal sphincter function is disturbed (achalasia, diffuse oesophageal spasm), or the amplitudes of peristaltic contractions are abnormally high (nutcracker oesophagus). This article focuses on the pathophysiology of achalasia and nutcracker oesophagus. There is evidence that achalasia and nutcracker oesophagus should not be considered parts of one and the same range of diseases.
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PMID:Primary oesophageal motility disorders: how primary are they? 1065 92

We have evaluated esophageal tone in two different conditions that, in some cases, similarly impair phasic esophageal motility. Studies were performed in 14 healthy volunteers, 10 patients with total esophageal aperistalsis secondary to gastroesophageal reflux disease (GERD), and 25 untreated achalasia patients. We quantified esophageal compliance and relaxation induced by a nitric oxide donor using a barostat. Intraesophageal volume at a minimal distending pressure (2 mmHg) was not significantly different among all three groups (4.1 +/- 0.7, 3.8 +/- 0.7, and 4.2 +/- 1.2 ml for healthy, GERD, and achalasia groups, respectively). Esophageal compliance was significantly increased (P < 0.05 vs. healthy group) in the two groups of patients with aperistalsis (1.9 +/- 0.2, 3.0 +/- 0.2, and 3.1 +/- 0.3 ml/mmHg for healthy, GERD, and achalasia groups, respectively). Esophageal relaxation was decreased in GERD patients (Delta diameter: 0.4 +/- 0.1 cm) and increased in achalasia patients (Delta diameter: 1.3 +/- 0.4 cm) relative to healthy subjects (Delta diameter: 0.9 +/- 0.2 cm) (P < 0.05 for GERD vs. achalasia and healthy groups). Our results indicate that diseases that similarly impair phasic esophageal motility may affect esophageal tone differently.
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PMID:Esophageal tone in patients with total aperistalsis: gastroesophageal reflux disease versus achalasia. 1091 47

The esophagus is a muscular conduit connecting the pharynx and the stomach. Its function is controlled by an intrinsic nervous system and by input from the central nervous system through the vagus nerve. Peristalsis in its striated muscle is directed by sequential vagal excitation arising in the brain stem, whereas peristalsis in its smooth muscle involves complex interactions among the central and peripheral neural systems and the smooth muscle elements of the esophagus. The peripheral neuronal elements responsible for producing esophageal off-response, relaxation of the lower esophageal sphincter, and hyperpolarization of the circular esophageal muscle cells reside in the myenteric plexus of the esophagus. For many years these nerves were considered nonadrenergic and noncholinergic because the inhibitory neurotransmitter released on their activation was unknown. We now know that nitric oxide or a related compound is that inhibitory neurotransmitter. The primary excitatory neurotransmitter controlling esophageal motor function is acetylcholine. Some disorders of esophageal motor function, including diffuse esophageal spasm and achalasia, may result from defects in or an imbalance between these excitatory and inhibitory neuromuscular systems.
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PMID:Neuromuscular control of esophageal peristalsis. 1098 Sep 48

Achalasia is a rare but important condition affecting the myenteric neurons of the esophagus. A number of studies have provided evidence for the preservation of cholinergic innervation to the esophagus in achalasia. This forms the rationale for the treatment of achalasia with botulinum toxin. Identification of nitric oxide as the primary inhibitory neurotransmitter of the gastrointestinal tract has improved our understanding of the pathophysiology of primary achalasia. Neurons containing nitric oxide are absent within the myenteric plexuses of patients with achalasia, and the experimental inhibition of nitric oxide produces a picture that manometrically mimics achalasia. Recent advances have provided insights into the genetic basis and pathogenesis of a growing number of secondary forms of achalasia. Examples of such secondary disorders include Allgrove's syndrome, autoimmune polyglandular syndrome, and multiple endocrine neoplasia type 2B.
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PMID:Pathophysiology of achalasia. 1098 Sep 49

The propagation of oesophageal peristaltic contractions and lower oesophageal sphincter (LOS) relaxation depends on neural release of nitric oxide (NO) which acts to increase intracellular cGMP. Sildenafil, a phosphodiesterase-5 inhibitor that increases cGMP, reduces basal LOS pressure in patients with achalasia. We investigated the effect of sildenafil on the propagation of oesophageal contractions and LOS relaxation in the cat. Oesophageal manometry was performed in five cats under light sedation. Peristaltic contractions were monitored at 1, 2, 3, 4 and 8 cm proximal to the LOS, at the LOS using a Dent sleeve, and at 3 cm distal to the upper oesophageal sphincter. Swallow-induced oesophageal contractions and LOS relaxation were recorded during 30 min before and 30 min after intravenous administration of sildenafil. Sildenafil reduced the amplitude of oesophageal contractions only in the smooth muscle oesophagus. The latency from swallow to distal oesophageal contractions was significantly delayed. LOS pressure was significantly reduced but the relaxation nadir was not modified by sildenafil. Sildenafil has profound effects on oesophageal motility: it modifies propagation and amplitude of oesophageal contractions and reduces LOS pressure. Slowing down the propagation of contractions in the transitional zone between the striated and smooth muscle can be a useful tool in patients with segmental aperistalsis or intermittent simultaneous contractions, while the effect on the LOS can benefit patients with achalasia.
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PMID:Effect of sildenafil, a phosphodiesterase-5 inhibitor, on oesophageal peristalsis and lower oesophageal sphincter function in cats. 1157 91


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