td-5108 and Acute-Disease

Acute colonic pseudo-obstruction is characterized by symptoms, signs and radiologic appearance of large bowel obstruction in the absence of a true mechanical obstruction. Several pharmacologic treatments have been proposed. We present a case of a patient with Guillain-Barré syndrome complicated by acute colonic pseudo-obstruction, who had a clinical response to tegaserod, a partial 5-hydroxytryptamine type-4 agonist. 5-Hydroxytryptamine type 4 agonists may be an option in the treatment of acute colonic pseudo-obstruction.

Topics: Acute Disease; Colonic Pseudo-Obstruction; Drug Partial Agonism; Guillain-Barre Syndrome; Humans; Indoles; Male; Middle Aged; Serotonin 5-HT4 Receptor Agonists

Distension-evoked reflex of rectorectal (R-R) contractions and rectointernal anal sphincter (R-IAS) relaxations can be generated in guinea pigs through an extrinsic sacral excitatory neural pathway (pelvic nerves) as well as intrinsic cholinergic excitatory and nitrergic inhibitory pathways. The aim of the present study was to create intrinsic R-R and R-IAS reflex models by pithing (destruction of the lumbar and sacral cords; PITH) and to evaluate whether the prokinetic benzamide mosapride, a 5-HT(4) receptor agonist, enhances these reflexes. The mechanical activities of the R-R and R-IAS were recorded in the anesthetized guinea pig on days 2-9 after PITH. Although the basal rectal pressure at distension after PITH was significantly lower than control, the reflex indexes of R-R contractions and synchronous R-IAS relaxations were unchanged between days 4 and 9 after PITH. The frequency of spontaneous rectal and IAS motility were also unchanged. Immunohistochemical studies revealed that the distribution of myenteric and intramuscular interstitial cells of Cajal (ICC) were not altered after PITH. Mosapride (0.1-1.0 mg/kg iv) dose-dependently increased both intrinsic R-R (maximum: 1.82) and R-IAS reflex indexes (maximum: 2.76) from control (1.0) 6-9 days after PITH. The 5-HT(4) receptor antagonist, GR-113808 (1.0 mg/kg iv) decreased the R-R and R-IAS reflex indexes by approximately 50% and antagonized the effect of mosapride (1.0 mg/kg iv). The present results indicate that mosapride moderately enhanced intrinsic R-R and R-IAS reflexes functionally compensated after deprivation of extrinsic nerves, mediated through endogenously active intrinsic 5-HT(4) receptors.

Topics: Acute Disease; Anal Canal; Animals; Benzamides; Chronic Disease; Denervation; Disease Models, Animal; Gastrointestinal Agents; Gastrointestinal Motility; Guinea Pigs; Indoles; Male; Morpholines; Rectum; Reflex; Serotonin 5-HT4 Receptor Agonists; Serotonin 5-HT4 Receptor Antagonists; Serotonin Antagonists; Spinal Cord Injuries; Sulfonamides