enkephalin--ala(2)-mephe(4)-gly(5)- and Colonic-Diseases--Functional

To study the effects of mu and kappa opioid receptor agonists and antagonists on the isolated colon strips of rats with cathartic colon.. Cathartic colon model was established by feeding rats with contact laxatives, and effects of mu and kappa opioid receptor agonists and antagonists on electricity-stimulated contraction of isolated colon strips of rats with cathartic colon were observed.. Compared with control group, exogenous mu and kappa agonists inhibited significantly electricity-stimulated contraction of strips of cathartic colon (8.50+/-0.89 mm, 6.24+/-0.91 mm, 3.35+/-0.6 mm vs 11.40+/-0.21 mm P<0.01; 8.98+/-0.69 mm, 6.89+/-0.71 mm, 4.43+/-0.99 mm vs 11.40+/-0.21 mm, P<0.01). In contrast, the exogenous mu antagonist significantly enhanced electricity-stimulated contraction of isolated colon strips (13.18+/-0.93 mm, 15.87+/-0.98 mm, 19.46+/-1.79 mm vs 11.40+/-0.21 mm, P<0.01), but kappa antagonist had no effect on the isolated colon strips of rats with cathartic colon.. Mu and kappa opioid receptors are involved in the regulation of colon motility of rats with cathartic colon.

Topics: Analgesics, Opioid; Animals; Cathartics; Colon; Colonic Diseases, Functional; Constipation; Electric Stimulation; Enkephalin, Ala(2)-MePhe(4)-Gly(5)-; Female; Gastrointestinal Motility; In Vitro Techniques; Male; Muscle Contraction; Naloxone; Narcotic Antagonists; Rats; Rats, Wistar; Receptors, Opioid, kappa; Receptors, Opioid, mu