AIM: To study the effects of mu and kappa opioid receptor agonists and antagonists on the isolated colon strips of rats with cathartic colon. METHODS: Cathartic colon model was established by feeding rats with contact...AIM: To study the effects of mu and kappa opioid receptor agonists and antagonists on the isolated colon strips of rats with cathartic colon. METHODS: 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. RESULTS: 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. CONCLUSION: Muand kappa opioid receptors are involved in the regulation of colon motility of rats with cathartic colon.展开更多
文摘AIM: To study the effects of mu and kappa opioid receptor agonists and antagonists on the isolated colon strips of rats with cathartic colon. METHODS: 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. RESULTS: 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. CONCLUSION: Muand kappa opioid receptors are involved in the regulation of colon motility of rats with cathartic colon.
