The action of loperamide in inhibiting prostaglandin-induced intestinal secretion in the rat.
1 The mechanisms by which loperamide inhibits the intestinal secretion induced by prostaglandin E2 were investigated in rat jejunum. 2 In vivo loperamide prevented prostaglandin-induced fluid secretion but did not reduce the associated rise in the transintestinal potential difference. 3 In intestinal sheets the electrical response to prostaglandin E2 was enhanced in the presence of loperamide. 4 The ionic basis of these changes was determined by measuring Na+ and Cl- fluxes across intestinal sheets. Loperamide did not reduce the prostaglandin-induced increase in net Cl- secretion, although it prevented the inhibition of mucosal-to-serosal Na+ movement. 5 Loperamide does not alter cyclic adenosine 3',5'-monophosphate (cyclic AMP) levels by a direct action at the enterocyte, since in isolated enterocytes neither basal nor prostaglandin-stimulated cyclic AMP levels were affected by the drug.
D000818:Animals; D002712:Chlorides / Q000378:metabolism; D000242:Cyclic AMP / Q000096:biosynthesis; D066298:In Vitro Techniques; D007413:Intestinal Mucosa / Q000378:metabolism* / Q000502:physiology; D008139:Loperamide / Q000494:pharmacology*; D008297:Male; D008564:Membrane Potentials / Q000187:drug effects; D010880:Piperidines / Q000494:pharmacology*; D011448:Prostaglandin Antagonists; D051381:Rats; D012964:Sodium / Q000378:metabolism
D002712:Chlorides; D010880:Piperidines; D011448:Prostaglandin Antagonists; D008139:Loperamide; D012964:Sodium; D000242:Cyclic AMP