Antinociceptive effects of intrathecally administered endothelin-1 in mice.
Intrathecal administration of endothelin-1 (ET-1) produced dose-dependent antinociceptive effects in the tail-flick test. The antinociceptive effects of ET-1 were attenuated significantly by pretreatment with naloxone and the delta receptor-selective antagonist naltrindole. The antinociceptive effects of ET-1 were also significantly attenuated by pretreatment with verapamil, an L-type Ca(2+)-channel blocker. These results suggest that the mechanism underlying the antinociceptive effects of ET-1 involves mediation, at least in part, by Ca(2+)-induced release of endogenous opioids, which act on delta-opioid receptors.
Department of Pharmacology, Faculty of Pharmaceutical Sciences, Hoshi University, Tokyo, Japan.
J
J
Kamei
H
H
Hitosugi
N
N
Kawashima
M
M
Misawa
Y
Y
Kasuya
D000818:Animals; D016232:Endothelins / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D006358:Hot Temperature; D007278:Injections, Spinal; D008297:Male; D051379:Mice; D008813:Mice, Inbred ICR; D009619:Nociceptors / Q000187:drug effects*; D010147:Pain Measurement; D013997:Time Factors; D014700:Verapamil / Q000494:pharmacology
D016232:Endothelins; D014700:Verapamil