Antinociceptive effect of smilaxin B administered intracerebroventricularly in the mouse.
We examined the antinociceptive effect of smilaxin B administered intracerebroventricularly (i.c.v.) in ICR mice. The tail-flick test was used as an analgesic assay. Smilaxin B showed a strong antinociceptive effect in a dose-dependent manner. Sulfated cholecystokinin (CCK-8s, 0.5 ng), muscimol (50ng), or MK-801 [(+/-)-5-methyl-10, 11-dihydro-5H-dibenzo [a,d]cyclohepten-5, 10-imine maleate, 1 microgram] injected i.c.v. significantly reduced inhibition of the tail-flick response induced by smilaxin B administered i.c.v. However, naloxone (2 microgram), baclofen (10 ng), or CNQX (6-cyano-7- nitroquinoxaline-2,3-dione, 0.5 microgram) injected i.c.v. did not affect inhibition of the tail-flick response induced by similaxin B administered i.c.v. The intrathecal (i.t.) injection of yohimbine (20 micrograms), but not methysergide (20 micrograms) and naloxone (2 microgram), significantly attenuated inhibition of the tail-flick response. induced by smilaxin B administered i.c.v. Our results suggest that GABAA or NMDA receptors but not opioid, GABAB, and non-NMDA receptors located at the supraspinal level may play important roles in the production of antinociception induced by smilaxin B administered supraspinally. Furthermore, smilaxin B administered supraspinally. may produce its antinociception by activating descending noradrenergic- but not opioidergic- and serotonergic-neurons.
Suh
H W
HW
Department of Pharmacology, College of Medicine, Hallym University, Kangwon-Do, Korea.
Song
D K
DK
Son
K H
KH
Woo
M H
MH
Do
J C
JC
Choi
Y S
YS
Lee
K H
KH
Kim
Y H
YH
D018750:6-Cyano-7-nitroquinoxaline-2,3-dione / Q000494:pharmacology; D000818:Animals; D001418:Baclofen / Q000494:pharmacology; D002552:Cerebral Ventricles / Q000187:drug effects / Q000502:physiology*; D016291:Dizocilpine Maleate / Q000494:pharmacology; D006027:Glycosides / Q000008:administration & dosage / Q000494:pharmacology*; D007276:Injections, Intraventricular; D007278:Injections, Spinal; D008297:Male; D008784:Methysergide / Q000494:pharmacology; D051379:Mice; D008813:Mice, Inbred ICR; D009118:Muscimol / Q000494:pharmacology; D009270:Naloxone / Q000494:pharmacology; D010146:Pain; D012844:Sincalide / Q000494:pharmacology; D013116:Spinal Cord / Q000187:drug effects / Q000502:physiology; D013150:Spirostans / Q000008:administration & dosage / Q000494:pharmacology*; D015016:Yohimbine / Q000494:pharmacology
D006027:Glycosides; D013150:Spirostans; C099794:smilaxin B; D009118:Muscimol; D015016:Yohimbine; D009270:Naloxone; D016291:Dizocilpine Maleate; D018750:6-Cyano-7-nitroquinoxaline-2,3-dione; D001418:Baclofen; D012844:Sincalide; D008784:Methysergide