Medycyna Wet. 66 (3), 196-200, 2010
Kania B.F., Wielgosz M.
Role of central κ-opioid receptors in the myoelectrical spike burst activity of the stomach wall in sheep
The aim of study was to evaluate the participation of central κ-opioidergic receptors in the modulatory/inhibitory effect of compound U50, 488H, a highly selective κ-opioid receptor agonist, on the spike burst activity of the rumen, reticulum and antrum prior to and 10 min after a one-minute i.c.v. infusion of norbinaltorphimine, a competitive κ-opioid receptor antagonist, in conscious sheep. U 50,488H was infused i.c.v. at doses of 0.1, 0.25 and 1.0 µg•kg-1 b.w., norbinaltorphimine at doses 10 times higher. All the doses of U 50,488H infused i.c.v. nonsignificantly changed myoelectrical activity of the wall of the rumen, reticulum and antrum. The effects of U 50,488H were not changed by norbinaltorphimine previously infused at doses of 1.0, 2.5 and 10.0 µg•kg-1 b.w. (i.e. at doses 10 times higher than U 50,488H). The results obtained indicate that central κ-opioid receptors did not participate in any action on myoelectrical activity of forestomachs and antrum in sheep.
Key words: κ-agonist, U 50,488H, κ-antagonist, norbinaltorphimine, gastric motility, sheep