Continuous cocaine administration enhances μ- but not δ-opioid receptor-mediated inhibition of adenylyl cyclase activity in nucleus accumbens

doi:10.1016/0014-2999(95)00828-4

European Journal of Pharmacology

Volume 297, Issues 1–2, 15 February 1996, Pages 187-191

https://doi.org/10.1016/0014-2999(95)00828-4 Get rights and content

Abstract

Cocaine alters opioid receptor densities in rat brain. To investigate the functional consequences of such opioid receptor changes, adenylyl cyclase activity was measured in rat nucleus accumbens and caudate putamen following continuous cocaine administration (50 mg/kg/day, 7 days). In the nucleus accumbens chronic cocaine led to an increase in both the number of μ-opioid receptors and the maximal inhibition of adenylyl cyclase activity by DAMGO ([d-Ala²,N-methyl-Phe⁴,Glyol]enkephalin). There was no effect on inhibition of adenylyl cyclase activity by DPDPE ([d-Pen²,d-Pen⁵]enkephalin). There were no changes in the caudate putamen. Thus, continuous cocaine administration for 7 days results in a selective increase in μ-opioid receptor-mediated effector function in the nucleus accumbens.

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Short communicationContinuous cocaine administration enhances μ- but not δ-opioid receptor-mediated inhibition of adenylyl cyclase activity in nucleus accumbens

Abstract

Brain Res.

Brain Res.

Brain Res.

Brain Res.

Effect of chronic cocaine treatment on μ- and δ-opioid receptor mRNA levels in dopaminergically innervated brain regions

J. Neurochem.

Naltrexone-induced upregulation of mu opioid receptors on 7315c cell and brain membranes: enhancement of opioid efficacy in inhibiting adenylyl cyclase

J. Pharmacol. Exp. Ther.

Tolerance to opioid narcotics. I. Tolerance to the ‘running fit’ caused by levorphanol in the mouse

J. Pharmacol. Exp. Ther.

Short communication
Continuous cocaine administration enhances μ- but not δ-opioid receptor-mediated inhibition of adenylyl cyclase activity in nucleus accumbens