Increased phosphorylated-mu-opioid receptor immunoreactivity in the mouse spinal cord following sciatic nerve ligation.
The present study was designed to determine whether a state of neuropathic pain induced by sciatic nerve ligation could alter phosphorylated-mu-opioid receptor-like immunoreactivity in the superficial dorsal horn of the mouse spinal cord. Mice with sciatic nerve ligation exhibited a significant suppression of the morphine-induced antinociception. Under this condition, phosphorylated-mu-opioid receptor-like immunoreactivity was clearly increased on the ipsilateral side in the superficial laminae of the L5 lumbar spinal dorsal horn in nerve-ligated mice. These findings suggest that the phosphorylation of the mu-opioid receptor in the spinal cord under a neuropathic pain-like state may, at least in part, contribute to the reduction in the antinociceptive effect produced by morphine in the mouse.
Narita
Minoru
M
Department of Toxicology, Hoshi University School of Pharmacy and Pharmaceutical Sciences, 2-4-41 Ebara, Shinagawa-ku, Tokyo 142-8501, Japan. narita@hoshi.ac.jp
Kuzumaki
Naoko
N
Suzuki
Masami
M
Narita
Michiko
M
Oe
Kousei
K
Yamazaki
Mitsuaki
M
Yajima
Yoshinori
Y
Suzuki
Tsutomu
T
D000344:Afferent Pathways / Q000187:drug effects / Q000378:metabolism / Q000503:physiopathology; D000818:Animals; D004195:Disease Models, Animal; D007839:Functional Laterality / Q000502:physiology; D008026:Ligation; D008297:Male; D051379:Mice; D008813:Mice, Inbred ICR; D009020:Morphine / Q000494:pharmacology; D009437:Neuralgia / Q000188:drug therapy / Q000378:metabolism* / Q000503:physiopathology; D010523:Peripheral Nervous System Diseases / Q000188:drug therapy / Q000378:metabolism* / Q000503:physiopathology; D010766:Phosphorylation / Q000187:drug effects; D020671:Posterior Horn Cells / Q000187:drug effects / Q000378:metabolism* / Q000473:pathology; D017450:Receptors, Opioid, mu / Q000187:drug effects / Q000378:metabolism*; D020426:Sciatic Neuropathy / Q000188:drug therapy / Q000378:metabolism / Q000503:physiopathology; D013116:Spinal Cord / Q000187:drug effects / Q000378:metabolism* / Q000473:pathology; D009435:Synaptic Transmission / Q000187:drug effects / Q000502:physiology; D015854:Up-Regulation / Q000187:drug effects / Q000502:physiology
D017450:Receptors, Opioid, mu; D009020:Morphine