抄録
The present study examined what kind of receptors are involved in the antinociception produced by intracerebroventricular (i.c.v.) administration of α,β-methylene-ATP using antagonists at adrenergic, serotonin or opioid receptors. Antinociceptive effect of α,β-methylene-ATP (10 nmol/rat) was significantly attenuated by subcutaneous pretreatment with propranolol and naloxone, but not phentolamine or methysergide, at a dose of 10 mg/kg. I.c.v. pretreatment with propranolol (100 nmol/rat), butoxamine (100 nmol/rat), ICI-118,551 (100 nmol/rat) and naloxone (30 nmol/rat) significantly attenuated the antinociceptive effect of α,β-methylene-ATP. However, i.c.v. pretreatment with atenolol (100 nmol/rat), naltrindole (30 nmol/rat) or nor-binaltorphimine (30 nmol/rat) did not show any significant effects. These results suggest that supraspinal β2-adrenergic and μ-opioid receptors are involved in the antinociceptive effect of i.c.v. administered α,β-methylene-ATP.
