Mu and delta opiate receptors in neuronal and astroglial primary cultures from various regions of the brain—coupling with adenylate cyclase, localisation on the same neurones and association with dopamine (D1) receptor adenylate cyclase

doi:10.1016/0028-3908(91)90170-G

Neuropharmacology

Volume 30, Issue 11, November 1991, Pages 1233-1239

https://doi.org/10.1016/0028-3908(91)90170-G Get rights and content

Abstract

Primary cultures, enriched in neurones or astroglial cells, from three phylogenetically different regions of the brain of the rat, the cerebral cortex, the striatum and the brain stem, were used to investigate the presence of opiate receptors, coupled to adenylate cyclase. Morphine was used as a μ-receptor agonist and [d-Ala², d-Leu⁵]-enkephalin (DADLE) was used as a δ -receptor agonist.

In the neuronal cultures, both ligands inhibited the prostaglandin (PG)E₁ -stimulated intracellular accumulation of cyclic AMP dose-dependently, with the most prominent effects seen in the cultures of striatum and with DADLE being more potent than morphine. The opiate receptor antagonist, naloxone reversed the effects. Morphine and DADLE, added together, inhibited the PGE₁-stimulated accumulation of cyclic AMP, less than the sum of the effects of each drug. Therefore, it might be that these opioid receptors are localized together on the same neurone. Striatal neurones contained dopamine receptors coupled to cyclic AMP, as second messenger. It was shown that the D₁ (dopamine) receptor-stimulated activity of adenylate cyclase was inhibited by the μ and δ opioid receptor ligands. Thus, interactions at the level of adenylate cyclase seem to exist between D₁, μ and δ opiate receptors.

In the astroglial enriched cultures, DADLE inhibited the PGE₁-induced accumulation of cyclic AMP, however, with a less prominent effect in the brain stem cultures. Morphine did not influence the basal or the PGE₁-stimulated intracellular accumulation of cyclic AMP in the cultures used and DADLE was less effective in inhibiting the PGE₁-induced accumulation of cyclic AMP in the astroglial cultures, than in the neuronal enriched cultures, indicating less developed δ receptor-second messenger efficacy in the astroglial cultures, than in the neuronal cultures. These results thus suggest the presence of δ receptors on astroglial cells in culture, while no μ receptors with cyclic AMP as second messenger were identified.

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Mu and delta opiate receptors in neuronal and astroglial primary cultures from various regions of the brain—coupling with adenylate cyclase, localisation on the same neurones and association with dopamine (D1) receptor adenylate cyclase

Abstract

Life Sci.

J. biol. Chem.

Neuropharmacology

Dev. Brain Res.

Life Sci.

Brain Res.

Neuropharmacology

Prog. Brain Res.

J. biol. Chem.

TINS

Brain Res.

J. biol. Chem.

Neuroscience

Neurosci. Lett.

Life Sci.

Eur. J. Pharmac.

J. biol. Chem.

Life Sci.

Inhibition of hormonally regulated adenylate cyclase by the βγ subunit of transducin

EMBO J.

Mu and delta opiate receptors coupled negatively to adenylate cyclase on embryonic neurones from the mouse striatum in primary cultures

J. Neurosci.

The a subunit of the GTP binding protein Gk opens atrial potassium channels

Science

Opiate receptor-mediated inhibition of adenylate cyclase in rat striatal plasma membranes

J. Neurochem.

Acute and chronic opiate-regulation of adenylate cyclase in brain: Specific effects in locus coeruleus

J. Pharmac. exp. Ther.

Both μ and δ opiate receptors exist on the same neuron

Science

Mu and delta opiate receptors in neuronal and astroglial primary cultures from various regions of the brain—coupling with adenylate cyclase, localisation on the same neurones and association with dopamine (D₁) receptor adenylate cyclase

The a subunit of the GTP binding protein G_k opens atrial potassium channels