title: Alpha-2 receptors in the gastrointestinal system: a new therapeutic approach.
abstract: Alpha-2 receptor activation mediates the inhibition of a number of gastrointestinal functions including gastric and intestinal secretions. Alpha-2 receptors are located in the brain and presynaptically on cholinergic nerve terminals; activation of either inhibits vagus nerve activity. Intestinal secretions are inhibited by postsynaptic alpha-2 receptors located on intestinal epithelial cells. Agents which selectively activate alpha-2 receptors in the gut may therefore be beneficial in treating gastric ulcers and diarrheal states. Two such agents which activate alpha-2 receptors in the gut are WHR-1370A [1-n-butoxy-3-(2,6-dimethylphenylcarbamoyl) guanidine hydrochloride] and lidamidine. WHR-1370A is a potent gastric antisecretory and antiulcer agent which inhibits the release of acetylcholine from the vagus nerve. WHR-1370A's activity is blocked by yohimbine. Lidamidine is a clinically effective antidiarrheal agent. Lidamidine's response is partially inhibited by yohimbine in animal diarrheal models. Alpha-2 agonists represent a new class of drugs which have a promising future in the treatment of gastrointestinal disorders.
mesh_terms: D000316:Adrenergic alpha-Agonists / Q000008:administration & dosage / Q000627:therapeutic use*; D000818:Animals; D000930:Antidiarrheals; D001921:Brain / Q000187:drug effects; D002217:Carbachol / Q000494:pharmacology; D003000:Clonidine / Q000008:administration & dosage / Q000494:pharmacology; D003543:Cysteamine / Q000494:pharmacology; D003847:Deoxyglucose / Q000494:pharmacology; D005744:Gastric Acid / Q000378:metabolism; D005755:Gastrins / Q000097:blood; D005769:Gastrointestinal Motility / Q000187:drug effects; D006801:Humans; D007276:Injections, Intraventricular; D009638:Norepinephrine / Q000494:pharmacology; D010437:Peptic Ulcer / Q000188:drug therapy*; D010671:Phenylurea Compounds / Q000008:administration & dosage / Q000627:therapeutic use*; D013997:Time Factors; D015016:Yohimbine / Q000494:pharmacology
chemical_list: D000316:Adrenergic alpha-Agonists; D000930:Antidiarrheals; D005755:Gastrins; D010671:Phenylurea Compounds; D015016:Yohimbine; D003543:Cysteamine; C042669:WHR 1370A; D002217:Carbachol; D003847:Deoxyglucose; D003000:Clonidine; C020918:lidamidine; D009638:Norepinephrine