Involvement of beta2-adrenergic and mu-opioid receptors in antinociception produced by intracerebroventricular administration of alpha,beta-methylene-ATP

• Published in: Japanese journal of pharmacology Vol. 86; no. 4; pp. 423 - 428
• Main Authors: Fukui, M, Nakagawa, T, Minami, M, Satoh, M
• Format: Journal Article
• Language: English
• Published: Japan 01.08.2001
• Subjects: Adenosine Triphosphate - administration & dosage; Adenosine Triphosphate - analogs & derivatives; Adenosine Triphosphate - antagonists & inhibitors; Adenosine Triphosphate - pharmacology; Adrenergic alpha-Antagonists - administration & dosage; Adrenergic alpha-Antagonists - pharmacology; Adrenergic beta-2 Receptor Antagonists; Adrenergic beta-Antagonists - administration & dosage; Adrenergic beta-Antagonists - pharmacology; Analgesics - administration & dosage; Analgesics - antagonists & inhibitors; Analgesics - pharmacology; Animals; Dose-Response Relationship, Drug; Injections, Intraventricular; Injections, Subcutaneous; Male; Narcotic Antagonists - administration & dosage; Narcotic Antagonists - pharmacology; Nociceptors - physiology; Pain Measurement - drug effects; Rats; Rats, Sprague-Dawley; Receptors, Adrenergic, beta-2 - physiology; Receptors, Opioid, mu - antagonists & inhibitors; Receptors, Opioid, mu - physiology; Receptors, Serotonin - physiology; Serotonin Antagonists - administration & dosage; Serotonin Antagonists - pharmacology; Time Factors
• ISSN: 0021-5198

The present study examined what kind of receptors are involved in the antinociception produced by intracerebroventricular (i.c.v.) administration of a,beta-methylene-ATP using antagonists at adrenergic, serotonin or opioid receptors. Antinociceptive effect of alpha,beta-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-I 18,551 (100 nmol/rat) and naloxone (30 nmol/rat) significantly attenuated the antinociceptive effect of alpha,beta-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 beta2-adrenergic and mu-opioid receptors are involved in the antinociceptive effect of i.c.v. administered alpha,beta-methylene-ATP.