Modulatory roles of the adenosine triphosphate P2x-purinoceptor in generation of the persistent nociception induced by subcutaneous bee venom injection in the conscious rat.
To study the role of adenosine triphosphate (ATP) P2x-purinoceptor in the persistent nociceptive response induced by subcutaneous (s.c.) bee venom injection, we used a selective P2x receptor antagonist, pyridoxal-phosphate-6-azophenyl-2',4'-disulfonic acid (PPADS), to evaluate whether spinal P2x receptor play a role in development of spontaneous persistent pain. Injection s.c. of bee venom into the plantar surface of one hindpaw in the conscious rat produces a monophasic, prolonged persistent nociception characterized by continuously flinching reflex of the injected paw for 1-2 h. Intrathecal (i.t.) pretreatment with PPADS at two lower doses of 5 and 10 microg resulted in suppression of the flinching reflex in a dose dependent manner with the inhibitory rate 37 and 44%, respectively, when compared with the control group; whereas i.t. PPADS at a higher dose of 30 microg failed to produce any inhibitory effect. This result suggests that activation of P2x-purinoceptor in the spinal cord contributes to the induction of bee venom-induced prolonged persistent pain. However, the antinociceptive effect of ATP P2x-purinoceptor antagonist such as PPADS on clinical pathological pain seems to be limited due to its lack of effectiveness at higher dose.
Zheng
J H
JH
Department of Anatomy and K.K. Leung Brain Research Centre, The Fourth Military Medical University, Xi'an, People's Republic of China.
Chen
J
J
D000255:Adenosine Triphosphate / Q000502:physiology*; D000700:Analgesics / Q000494:pharmacology / Q000627:therapeutic use; D000818:Animals; D001514:Bee Venoms / Q000008:administration & dosage / Q000633:toxicity*; D003243:Consciousness; D004195:Disease Models, Animal; D006614:Hindlimb; D006930:Hyperalgesia / Q000139:chemically induced / Q000503:physiopathology*; D007249:Inflammation / Q000139:chemically induced / Q000503:physiopathology; D007278:Injections, Spinal; D007279:Injections, Subcutaneous; D009619:Nociceptors / Q000187:drug effects*; D058919:Purinergic P2 Receptor Antagonists; D011732:Pyridoxal Phosphate / Q000031:analogs & derivatives / Q000494:pharmacology / Q000627:therapeutic use; D051381:Rats; D017207:Rats, Sprague-Dawley; D018048:Receptors, Purinergic P2 / Q000502:physiology*; D012018:Reflex / Q000187:drug effects; D013116:Spinal Cord / Q000503:physiopathology
D000700:Analgesics; D001514:Bee Venoms; D058919:Purinergic P2 Receptor Antagonists; D018048:Receptors, Purinergic P2; C077792:pyridoxal phosphate-6-azophenyl-2',4'-disulfonic acid; D011732:Pyridoxal Phosphate; D000255:Adenosine Triphosphate