Endogenous opioids and ATP-sensitive potassium channels are involved in the mediation of apomorphine-induced antinociception at the spinal level: a behavioral study in rats.
The effects of intrathecally (i.t.) administered glibenclamide, a blocker of adenosine triphosphate-sensitive potassium (K(ATP)) channels, or naloxone on the antinociception produced by i.t. apomorphine or morphine were observed and analyzed in rats by tail-flick (TF) test. The results showed that: (1) i.t. apomorphine produced a significant and dose-dependent antinociception, (2) the antinociception produced by i.t. apomorphine could be blocked dose-dependently by i.t. glibenclamide or naloxone, (3) the antinociception produced by i.t. morphine could also be blocked dose-dependently by i.t. glibenclamide. The results suggest that endogenous opioids and ATP-sensitive potassium channels might be involved in the mediation of apomorphine-induced antinociception at the spinal level.
Kang
Y M
YM
Department of Neurobiology, Shanxi Medical University, Taiyuan, People's Republic of China.
Hu
W M
WM
Qiao
J T
JT
D000255:Adenosine Triphosphate / Q000502:physiology*; D000818:Animals; D001058:Apomorphine / Q000494:pharmacology*; D018491:Dopamine Agonists / Q000494:pharmacology*; D004723:Endorphins / Q000502:physiology*; D005260:Female; D005905:Glyburide / Q000494:pharmacology; D007278:Injections, Spinal; D008297:Male; D009020:Morphine / Q000494:pharmacology; D009270:Naloxone / Q000494:pharmacology; D009292:Narcotic Antagonists / Q000494:pharmacology; D009294:Narcotics / Q000494:pharmacology; D009619:Nociceptors / Q000187:drug effects*; D010146:Pain / Q000503:physiopathology; D026902:Potassium Channel Blockers; D015221:Potassium Channels / Q000502:physiology*; D051381:Rats; D017208:Rats, Wistar; D011930:Reaction Time / Q000502:physiology; D013116:Spinal Cord / Q000187:drug effects* / Q000502:physiology*
D018491:Dopamine Agonists; D004723:Endorphins; D009292:Narcotic Antagonists; D009294:Narcotics; D026902:Potassium Channel Blockers; D015221:Potassium Channels; D009270:Naloxone; D009020:Morphine; D000255:Adenosine Triphosphate; D001058:Apomorphine; D005905:Glyburide