Antagonism of U-50,488H-induced antinociception by ginseng total saponins is dependent on serotonergic mechanisms.
Morphine-induced antinociception was prevented by pretreatment with ginseng total saponins in the tail-pinch and tail-flick tests carried out in mice. The antinociceptive effect of U-50,488H, a selective kappa-opioid receptor agonist, was prevented by naloxone, a nonselective opioid receptor antagonist, in the tail-pinch but not in the tail-flick test. However, U-50,488H-induced antinociception was prevented by ginseng total saponins in the tail-flick but not in the tail-pinch test. These results indicate that nonopioid mechanisms are involved in the antagonism of U-50,488H-induced antinociception by ginseng total saponins. In addition, the antagonism of U-50,488H-induced antinociception in mice pretreated with ginseng total saponins was abolished by pretreatment with a serotonin precursor, 5-hydroxytryptophan, but not by a noradrenaline precursor, L-dihydroxyphenylalanine, in the tail-flick test. Therefore, it appears that the antagonism of U-50,488H-induced antinociception by ginseng total saponins is dependent on serotonergic mechanisms.
Kim
H S
HS
Department of Pharmacology, College of Pharmacy, Chungbuk National University, Republic of Korea.
Oh
K W
KW
Rheu
H M
HM
Kim
S H
SH
D019900:3,4-Dichloro-N-methyl-N-(2-(1-pyrrolidinyl)-cyclohexyl)-benzeneacetamide, (trans)-Isomer; D000700:Analgesics / Q000037:antagonists & inhibitors*; D000818:Animals; D004295:Dihydroxyphenylalanine / Q000494:pharmacology; D007980:Levodopa / Q000494:pharmacology; D008297:Male; D051379:Mice; D008813:Mice, Inbred ICR; D009020:Morphine / Q000494:pharmacology; D009270:Naloxone / Q000494:pharmacology; D005894:Panax; D010946:Plants, Medicinal; D011759:Pyrrolidines / Q000037:antagonists & inhibitors*; D011930:Reaction Time / Q000187:drug effects; D012503:Saponins / Q000494:pharmacology*; D012701:Serotonin / Q000494:pharmacology / Q000502:physiology*
D000700:Analgesics; D011759:Pyrrolidines; D012503:Saponins; D012701:Serotonin; D009270:Naloxone; D007980:Levodopa; D004295:Dihydroxyphenylalanine; D019900:3,4-Dichloro-N-methyl-N-(2-(1-pyrrolidinyl)-cyclohexyl)-benzeneacetamide, (trans)-Isomer; D009020:Morphine