[Effect of morphine on pain threshold and C-fos expression induced by substance P].
Using pain measurement and immunohistochemistry, we have observed that the intrathecal injection (it) SP produced dose-related pain response. A larger dose of SP (5 micrograms, 10 micrograms) could reduce the pain threshold and evoke c-fos expression, but no obvious effect was produced by a smaller dose of SP (0.5 microgram, 1 microgram). Morphine (it) not only increased the pain threshold, but also inhibited pain response and c-fos expression of spinal cord induced by it SP, the effects could be reversed by naloxone.
Ruan
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Department of Physiology, Third Military Medical College, Chongqing.
Li
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Li
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D000701:Analgesics, Opioid / Q000494:pharmacology*; D000818:Animals; D005260:Female; D007278:Injections, Spinal; D008297:Male; D009020:Morphine / Q000494:pharmacology*; D010147:Pain Measurement; D017288:Pain Threshold / Q000187:drug effects*; D016760:Proto-Oncogene Proteins c-fos / Q000096:biosynthesis*; D051381:Rats; D017208:Rats, Wistar; D013116:Spinal Cord / Q000378:metabolism; D013373:Substance P / Q000494:pharmacology*
D000701:Analgesics, Opioid; D016760:Proto-Oncogene Proteins c-fos; D013373:Substance P; D009020:Morphine