Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0022104 (irritable bowel syndrome)
 8,033 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Although it is unclear to what extent irritable bowel syndrome (IBS) symptoms represent a normal perception of abnormal function or an abnormal perception of normal function, many believe that IBS constitutes the clinical expression of an underlying motility disorder, affecting primarily the mid- and lower gut. Indeed, transit and contractile abnormalities have been demonstrated with sophisticated techniques in a subset of patients with IBS. As a consequence, drugs affecting gastrointestinal (GI) motility have been widely employed with the aim of correcting the major IBS manifestations, ie, pain and altered bowel function. Unfortunately, no single drug has proven to be effective in treating IBS symptom complex. In addition, the use of some medications has often been associated with unpleasant side effects. Therefore, the search for a truly effective and safe drug to control motility disturbances in IBS continues. Several classes of drugs look promising and are under evaluation. Among the motor-inhibiting drugs, gut selective muscarinic antagonists (such as zamifenacin and darifenacin), neurokinin2 antagonists (such as MEN-10627 and MEN-11420), beta3-adrenoreceptor agonists (eg, SR-58611A) and GI-selective calcium channel blockers (eg, pinaverium bromide and octylonium) are able to decrease painful contractile activity in the gut (antispasmodic effect), without significantly affecting other body functions. Novel mechanisms to stimulate GI motility and transit include blockade of cholecystokinin (CCK)A receptors and stimulation of motilin receptors. Loxiglumide (and its dextroisomer, dexloxiglumide) is the only CCKA receptor antagonist that is being evaluated clinically. This drug accelerates gastric emptying and colonic transit, thereby increasing the number of bowel movements in patients with chronic constipation. It is also able to reduce visceral perception. Erythromycin and related 14-member macrolide compounds inhibit the binding of motilin to its receptors on GI smooth muscle and, therefore, act as motilin agonists. This antibiotic accelerates gastric emptying and shortens orocecal transit time. In the large bowel a significant decrease in transit is observed only in the right colon, which suggests a shift in fecal distribution. Several 'motilinomimetics' have been synthesized. Their development depends on the lack of antimicrobial activity and the absence of fading of the prokinetic effect during prolonged administration. 5-hydroxytryptamine (5-HT)4 agonists with significant pharmacological effects on the mid- and distal gut (such as prucalopride and tegaserod) are available for human use. These 'enterokinetic' compounds are useful for treating constipation-predominant IBS patients. 5-HT3 receptor antagonists also possess a number of interesting pharmacological properties that may make them suitable for treatment of IBS. Besides decreasing colonic sensitivity to distension, these drugs prolong intestinal transit and may be particularly useful in diarrhea-predominant IBS. Finally, when administered in small pulsed doses, octreotide, besides reducing the perception of rectal distension, accelerates intestinal transit, although other evidence disputes such an effect.
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PMID:Management of irritable bowel syndrome: novel approaches to the pharmacology of gut motility. 1020 10

Irritable bowel syndrome is characterized by visceral hyperalgesia commonly associated with stress and inflammatory processes. We investigated the role of tachykinin NK2 receptors in the ability of trinitrobenzenesulphonic acid (TNBS) and stress to enhance the sensitivity of the rat rectum to distension using a selective tachykinin NK2 receptor antagonist (MEN 11420). Rats were fitted with electrodes implanted in the striated muscles of the abdomen. Rectal distension (RD) was performed with a balloon inflated by steps of 0.4 ml from 0 to 1.6 ml. Five groups were submitted to RD performed 3 days before and after intrarectal instillation of TNBS. Fifteen minutes before RD, rats were treated with saline or MEN 11420 (5 - 100 microg kg(-1) i.v.). Two other groups, submitted to 2 h restraint or sham stress sessions were randomly treated i.v. with saline or MEN 11420 (10 - 200 microg kg(-1)) prior to RD applied 20 min later. The basal response to RD was characterized by a significant increase in the number of abdominal contractions. This response occurred with a threshold volume of 0.8 ml and was dose-dependently reduced by MEN 11420 (5 - 100 microg kg(-1) i.v.). Rectal inflammation lowered the volume of distension producing abdominal contractions to 0.4 ml (allodynia). This effect was either reduced or suppressed by MEN 11420. A similar allodynia was observed after a stress session and this effect was reduced (49%) or suppressed by MEN 11420 at 200 and 100 microg kg(-1), respectively. Tachykinin NK2 receptors are involved in rectal hypersensitivity associated with inflammation and stress. British Journal of Pharmacology (2000) 129, 193 - 199
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PMID:Role of tachykinin NK2 receptors in normal and altered rectal sensitivity in rats. 1069 20

We prospectively evaluated the initial presenting symptoms in 261 patients with Zollinger-Ellison syndrome (ZES) over a 25-year period. Twenty-two percent of the patients had multiple endocrine neoplasia-type 1 (MEN-1) with ZES. Mean age at onset was 41.1 +/- 0.7 years, with MEN-1 patients presenting at a younger age than those with sporadic ZES (p < 0.0001). Three percent of the patients had onset of the disease < age 20 years, and 7% > 60 years. A mean delay to diagnosis of 5.2 +/- 0.4 years occurred in all patients. A shorter duration of symptoms was noted in female patients and in patients with liver metastases. Abdominal pain and diarrhea were the most common symptoms, present in 75% and 73% of patients, respectively. Heartburn and weight loss, which were uncommonly reported in early series, were present in 44% and 17% of patients, respectively. Gastrointestinal bleeding was the initial presentation in a quarter of the patients. Patients rarely presented with only 1 symptom (11%); pain and diarrhea was the most frequent combination, occurring in 55% of patients. An important presenting sign that should suggest ZES is prominent gastric body folds, which were noted on endoscopy in 94% of patients; however, esophageal stricture and duodenal or pyloric scarring, reported in numerous case reports, were noted in only 4%-10%. Patients with MEN-1 presented less frequently with pain and bleeding and more frequently with nephrolithiasis. Comparing the clinical presentation before the introduction of histamine H2-receptor antagonists (pre-1980, n = 36), after the introduction of histamine H2-receptor antagonists (1981-1989, n = 118), and after the introduction of proton pump inhibitors (PPIs) (> 1990, n = 106) demonstrates no change in age of onset; delay in diagnosis; frequency of pain, diarrhea, weight loss; or frequency of complications of severe peptic disease (bleeding, perforations, esophageal strictures, pyloric scarring). Since the introduction of histamine H2-receptor antagonists, fewer patients had a previous history of gastric acid-reducing surgery or total gastrectomy. Only 1 patient evaluated after 1980 had a total gastrectomy, and this was done in 1977. The location of the primary tumor in general had a minimal effect on the clinical presentation, causing no effect on the age at presentation, delay in diagnosis, frequency of nephrolithiasis, or severity of disease (strictures, perforations, peptic ulcers, pyloric scarring). Disease extent had a minimal effect on symptoms, with only bleeding being more frequent in patients with localized disease. Patients with advanced disease presented at a later age and with a shorter disease history (p = 0.001), were less likely to have MEN-1 (p = 0.0087), and tended to have diarrhea more frequently (p = 0.079). A correct diagnosis of ZES was made by the referring physician initially in only 3% of the patients. The most common misdiagnosis made were idiopathic peptic ulcer disease (71%), idiopathic gastroesophageal reflux disease (GERD) (7%), and chronic idiopathic diarrhea (7%). Other less common misdiagnosis were Crohn disease (2%) and various diarrhea diseases (celiac sprue [3%], irritable bowel syndrome [3%], infectious diarrhea [2%], and lactose intolerance [1%]). Other medical disorders were present in 55% of all patients; patients with sporadic disease had fewer other medical disorders than patients with MEN-1 (45% versus 90%, p < 0.00001). Hyperparathyroidism and a previous history of kidney stones were significantly more frequent in patients with MEN-1 than in those with sporadic ZES. Pulmonary disorders and other malignancies were also more common in patients with MEN-1. These results demonstrate that abdominal pain, diarrhea, and heartburn are the most common presenting symptoms in ZES and that heartburn and diarrhea are more common than previously reported. The presence of weight loss especially with abdominal pain, diarrhea, or heartburn is an important clue suggesting the presence of gastrinoma. The presence of prominent gastric body folds, a clinical sign that has not been appreciated, is another important clue to the diagnosis of ZES. Patients with MEN-1 presented at an earlier age; however, in general, the initial symptoms were similar to patients without MEN-1. Gastrinoma extent and location have minimal effects on the clinical presentation. Overall, neither the introduction of successful antisecretory therapy nor widespread publication about ZES, attempting to increase awareness, has shortened the delay in diagnosis or reduced the incidence of patients presenting with peptic complications. The introduction of successful antisecretory therapy, however, has dramatically decreased the rate of surgery in controlling the acid secretion and likely led to patients presenting with less severe symptoms and fewer complications. (ABSTRACT TRUNCATED)
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PMID:Zollinger-Ellison syndrome. Clinical presentation in 261 patients. 1114 36

Tachykinin NK2 receptors are implicated in nociception and the control of intestinal motility. Here we examined their involvement in responses of spinal lumbosacral neurons with colon input to distension of normal or inflamed colon in anesthetized rats. The responses of single neurons to colorectal distension (5-80 mmHg), to electrical stimulation of the pelvic nerve (bypassing sensory receptors) and to somatic stimulation were characterized. The effect of cumulative doses of an NK2 receptor antagonist, MEN 11420 (10-1000 microg kg(-1) IV), on responses to these stimuli was tested in control conditions (n=6), or 45 min after intracolonic instillation of acetic acid (n=6). After colonic inflammation, neuronal responses to colorectal distension and pelvic nerve stimulation were significantly greater. MEN 11420 dose-dependently inhibited the enhanced responses to colorectal distension after inflammation (ID50=402+/-14 microg kg(-1)), but had no significant effect on responses to pelvic nerve stimulation or distension of the normal colon, suggesting a peripheral action selective for the inflamed colon. We conclude that MEN 11420 possesses peripheral anti-hyperalgesic effects on neuronal responses to colorectal distension. These results provide a neurophysiological basis for a possible use of tachykinin NK2 receptor antagonists in treating abdominal pain in irritable bowel syndrome patients.
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PMID:Responses of rat spinal neurons to distension of inflamed colon: role of tachykinin NK2 receptors. 1131 97