UI - 000068

AU - Delay-Goyet P

AU - Kayser V

AU - Zajac JM

AU - Guilbaud G

AU - Besson JM

AU - Roques BP

TI - Lack of significant changes in mu, delta opioid binding sites and neutral endopeptidase EC

3.4.24.11 in the brain and spinal cord of arthritic rats

AB - The possible changes in neutral endopeptidase EC 3.4.24.11 ("enkephalinase", NEP), mu and delta

opioid binding sites, were investigated using in vitro quantitative radioautography in various regions of the

central nervous system of the Freund's adjuvant-induced arthritic rat, a model of chronic pain. Enkephalinase

was labeled by a specific tritiated inhibitor, [3H]N-[(2RS)-3-hydroxyaminocarbonyl-2-benzyl-1-

oxopropyl]glycine ([3H]HACBO-Gly), while mu and delta opioid binding sites were selectively labelled with

[3H]Tyr-D-Ala-Gly-(Me)Phe-Gly-ol ([3H]DAGO) and [3H]Tyr-D-Thr-Gly-Phe-Leu-Thr ([3H]DTLFT),

respectively. As compared to controls, no significant modifications were found in NEP, mu or delta binding

sites at both supraspinal and spinal levels of arthritic rats. These results suggest that the enhanced efficiency

of exogenous opioids or endogenous enkephalins, reported to occur in this model of chronic inflammatory

pain, are not directly related to changes in mu and delta opioid binding sites or steady state levels of NEP

SO - Neuropharmacology 1989;28:1341-134