dextro-Naloxone or levo-naloxone reverses the attenuation of morphine antinociception induced by lipopolysaccharide in the mouse spinal cord via a non-opioid mechanism.
Glial stimulation by intrathecal injection of lipopolysaccharide (LPS) attenuated the tail-flick inhibition produced by morphine given intrathecally in the spinal cord of the male CD-1 mice. The phenomenon has been defined as antianalgesia. The effects of dextro-naloxone or levo-naloxone on the attenuation of morphine-produced tail-flick inhibition induced by LPS were then studied. Pretreatment with dextro-naloxone or levo-naloxone reversed the attenuation of the morphine-produced tail-flick inhibition induced by LPS. Pretreatment with dextro-naloxone or levo-naloxone alone did not affect the morphine-produced tail-flick inhibition. It is concluded that dextro-naloxone and levo-naloxone block the LPS-induced antianalgesia against morphine antinociception via a non-opioid mechanism.
Wu
Hsiang-En
HE
Department of Anesthesiology, Medical College of Wisconsin, Milwaukee, WI 53226, USA.
Sun
Han-Sen
HS
Cheng
Caleb W
CW
Terashvili
Maia
M
Tseng
Leon F
LF
D000701:Analgesics, Opioid / Q000008:administration & dosage*; D000818:Animals; D007278:Injections, Spinal; D008070:Lipopolysaccharides / Q000008:administration & dosage*; D008297:Male; D051379:Mice; D009020:Morphine / Q000008:administration & dosage; D009270:Naloxone / Q000008:administration & dosage*; D009292:Narcotic Antagonists / Q000008:administration & dosage*; D009457:Neuroglia / Q000187:drug effects / Q000378:metabolism; D010146:Pain / Q000139:chemically induced / Q000503:physiopathology*; D013116:Spinal Cord / Q000187:drug effects* / Q000378:metabolism; D013237:Stereoisomerism
D000701:Analgesics, Opioid; D008070:Lipopolysaccharides; D009292:Narcotic Antagonists; D009270:Naloxone; D009020:Morphine