TY - JOUR
T1 - Delayed application of MK-801 attenuates development of morphine tolerance in rats
AU - Marek, Przemyslaw
AU - Ben-Eliyahu, Shamgar
AU - Vaccarino, Anthony L.
AU - Liebeskind, John C.
N1 - Funding Information:
This research was supported by NIH Grant NS07628 and an Unrestricted Pain Research Grant from the Bristol-Myers Squibb 1 Andin6, P., Lehmann, A., Ellr6n, K., Wennberg, E., Kjellmer, I., Nielsen, T. and Hagberg, H., The excitatory amino acid antagonist kynurenic acid administered after hypoxic-ischemia in neonatal rats offers neuroprotection, Neurosci. Lett., 90 (1988) 208-212. 2 Benveniste, H., Drejer, J., Schousboe, A. and Diemer, N.H., Elevation of the extracellular concentration of glutamate and aspartate in rat hippocampus during transient cerebral ischemia monitored by intracerebral microdialysis, J. Neurochem., 43 (1984) 1369-1374. 3 Choi, D. W., Methods for antagonizing glutamate neurotoxicity, Cerebrovasc. Brain Metabol. Rev., 2 (1990) 105-147 4 Collingridge, G. L. and Bliss, T. V. P., NMDA receptors: their role in long-term potentiation, Trends Neurosci., 10 (1987) 288-294. 5 Fagni, L., Baundry, M. and Lynch, G., Classification and properties of acidic amino acid receptors in hippocampus. I. Electrophysiological studies of an apparent desensitization and interactions with drugs which block transmission, Z Neurosci., 3 (1983) 1538-1546. 6 Foster, A. C., Gill, R. and Woodruff, G. N., Neuroprotective effects of MK-801 in vivo: selectivity and evidence for delayed degeneration mediated by NMDA receptor activation, J. Neu-rosci., 8 (1988) 4745-4754. 7 Gill, R., Foster, A.C. and Woodruff, G.N., MK-801 is neuro-protective in gerbils when administered in the post-ischemic period, Neuroscience, 25 (1988) 847-855. 8 Hagberg, H., Lehmann, A., Sandberg, M., Nystr6m, B., Jacobson, I. and Hamberger, A., Ischemia-induced shift of inhibitory and excitatory amino acids from intra-to extracellular compartments, J. Cereb. Blood Flow Metabol., 5 (1985) 413-419. 9 Hagberg, H., Andersson, P., Kjellmer, I., Thiringer, K., and Thordstein, M., Extracellular overflow of glutamate, aspartate, GABA and taurine in the cortex and basal ganglia of fetal lambs during hypoxia-ischemia, Neurosci. Lett., 78 (1987) 311-317. 10 Jacquet, Y. E, The NMDA receptor: central role in pain inhibition in rat periaqueductal gray, Eur. J. Pharmacol., 154 (1988) 271-276.
Funding Information:
Company. A.L.V. is supported by a postdoctoral fellowship from the Natural Sciences and Engineering Research Council of Canada.
PY - 1991/8/30
Y1 - 1991/8/30
N2 - To investigate the possible involvement of enduring or delayed changes at the N-methyl-d-aspartic acid (NMDA) receptor in the mechanisms of morphine tolerance, rats were treated with the specific NMDA receptor antagonist, MK-801 (0.15 mg/kg) 2 h after morphine injection (20 mg/kg) during a 4-day induction period of tolerance. On the fifth day rats were injected only with morphine (15 mg/kg), and analgesia was assessed using the hot-plate test. Morphine tolerance was significantly reduced by MK-801. These findings suggest that long-lasting or delayed changes at the NMDA receptor underlie the development of morphine tolerance Moreover, because MK-801 was delivered 2 h after morphine and therefore could not serve as a cue for morphine administration, these findings indicate that the attenuating effect of MK-801 on the development of morphine tolerance is not attributable to state-dependent learning.
AB - To investigate the possible involvement of enduring or delayed changes at the N-methyl-d-aspartic acid (NMDA) receptor in the mechanisms of morphine tolerance, rats were treated with the specific NMDA receptor antagonist, MK-801 (0.15 mg/kg) 2 h after morphine injection (20 mg/kg) during a 4-day induction period of tolerance. On the fifth day rats were injected only with morphine (15 mg/kg), and analgesia was assessed using the hot-plate test. Morphine tolerance was significantly reduced by MK-801. These findings suggest that long-lasting or delayed changes at the NMDA receptor underlie the development of morphine tolerance Moreover, because MK-801 was delivered 2 h after morphine and therefore could not serve as a cue for morphine administration, these findings indicate that the attenuating effect of MK-801 on the development of morphine tolerance is not attributable to state-dependent learning.
KW - Analgesia
KW - MK-801
KW - Morphine
KW - N-Methyl-d-aspartic acid
KW - State-dependent learning
KW - Tolerance
UR - http://www.scopus.com/inward/record.url?scp=0025883699&partnerID=8YFLogxK
U2 - 10.1016/0006-8993(91)90736-F
DO - 10.1016/0006-8993(91)90736-F
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AN - SCOPUS:0025883699
VL - 558
SP - 163
EP - 165
JO - Brain Research
JF - Brain Research
SN - 0006-8993
IS - 1
ER -