Cj. Nelson et Dt. Lysle, Involvement of substance P and central opioid receptors in morphine modulation of the CHS response, J NEUROIMM, 115(1-2), 2001, pp. 101-110
Morphine administration prior to challenge with the antigen 2,4-dinitro-flu
orobenzene increases the contact hypersensitivity (CHS) response in rats. T
he present study extended these findings by showing that central, but not s
ystemic, administration of N-methylnaltrexone antagonized the morphine-indu
ced enhancement of the CHS response. The importance of the neuroimmune medi
ator substance P was shown via the attenuation of the morphine-induced enha
ncement following both systemic and topical administration of the NK-1 anta
gonist WIN51,708. Taken together, the findings of the present study provide
new data showing that central opioid receptors and peripheral substance P
are involved in the morphine-induced enhancement of the CHS response. (C) 2
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