Reversal of the effects of centrally-administered @entity1286 on colonic motility in @entity235 by the XXXX receptor antagonist @entity5757 .

@entity7862 @entity235 @entity1510 @entity1245 @entity5757 @entity1286
The effects of intravenous (i.v.) and intracerebroventricular (i.c.v.) administration of @entity1286 on jejunal and colonic motility were investigated in conscious @entity235 chronically prepared with strain gage transducers and compared to those of i.c.v. @entity7862 , a highly selective opiate mu agonist. @entity1286 i.v. (100 micrograms/kg) and i.c.v. (10 micrograms/kg) administered 3 hrs after a meal stimulated colonic motility for 3-5 hrs and induced a phase 3 on the jejunum, which appeared after a 15-60 min delay following i.c.v. administration. These effects were reproduced by @entity7862 administration at doses of 2 micrograms/kg i.v. and 0.2 micrograms/kg i.c.v. The effects of i.v., but not those of i.c.v., @entity1286 and @entity7862 on jejunal and colonic motility were blocked by a previous administration of @entity1510 (100 micrograms/kg i.v.). The colonic stimulation but not the jejunal phase 3 induced by i.c.v. @entity1286 and @entity7862 were blocked by @entity5757 (1 mg/kg i.v.), a selective @entity1245 antagonist. The colonic stimulation induced by i.v. @entity1286 or @entity7862 was not modify by i.v. @entity5757 . It is concluded that i.c.v. administration of mu agonist involved @entity1245 but not opiate receptors to stimulate colonic motility in @entity235 .
