Agonist-selective effects of opioid receptor ligands on cytosolic calcium concentration in rat striatal neurons

作者：Brailoiu G Cristina; Deliu Elena; Hooper Robert; Dun Nae J; Undieh Ashiwel S; Adler Martin W; Benamar Khalid^*; Brailoiu Eugen

来源：Drug and Alcohol Dependence, 2012, 123(1-3): 277-281.

DOI：10.1016/j.drugalcdep.2011.11.021

• Calcium imaging
• Opioid receptors
• Striatum

Background: Buprenorphine is an opioid receptor ligand whose mechanism of action is incompletely understood. %26lt;br%26gt;Methods: Using Ca2+ imaging, we assessed the effects of buprenorphine, beta-endorphin, and morphine on cytosolic Ca2+ concentration [Ca2+](i), in rat striatal neurons. %26lt;br%26gt;Results: Buprenorphine (0.01-1 mu M) increased [Ca2+](i) in a dose-dependent manner in a subpopulation of rat striatal neurons. The effect of buprenorphine was largely reduced by naloxone, a non-selective opioid receptor antagonist, but not by mu, kappa, delta or NOP-selective antagonists. beta-Endorphin (0.1 mu M) increased [Ca2+](i) with a lower amplitude and slower time course than buprenorphine. Similar to buprenorphine, the effect of beta-endorphin was markedly decreased by naloxone, but not by opioid-selective antagonists. Morphine (0.1-10 mu M), did not affect [Ca2+](i) in striatal neurons. %26lt;br%26gt;Conclusions: Our results suggest that buprenorphine and beta-endorphin act on a distinct type/subtype of plasmalemmal opioid receptors or activate intracellular opioid-like receptor(s) in rat striatal neurons.

• 出版日期2012-6-1