Department of Pharmacology, Temple University School of Medicine, Philadelphia, PA 19140, USA.
Drug Alcohol Depend. 2012 Jun 1;123(1-3):277-81. doi: 10.1016/j.drugalcdep.2011.11.021. Epub 2011 Dec 21.
Buprenorphine is an opioid receptor ligand whose mechanism of action is incompletely understood.
Using Ca(2+) imaging, we assessed the effects of buprenorphine, β-endorphin, and morphine on cytosolic Ca(2+) concentration Ca(2+), in rat striatal neurons.
Buprenorphine (0.01-1 μM) increased Ca(2+) 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 μ, κ, δ or NOP-selective antagonists. β-Endorphin (0.1 μM) increased Ca(2+) with a lower amplitude and slower time course than buprenorphine. Similar to buprenorphine, the effect of β-endorphin was markedly decreased by naloxone, but not by opioid-selective antagonists. Morphine (0.1-10 μM), did not affect Ca(2+) in striatal neurons.
Our results suggest that buprenorphine and β-endorphin act on a distinct type/subtype of plasmalemmal opioid receptors or activate intracellular opioid-like receptor(s) in rat striatal neurons.
丁丙诺啡是一种阿片受体配体，其作用机制尚不完全清楚。
我们使用 Ca(2+) 成像技术，评估了丁丙诺啡、β-内啡肽和吗啡对大鼠纹状体神经元细胞浆钙离子浓度(Ca(2+))的影响。
丁丙诺啡（0.01-1 μM）以剂量依赖的方式增加大鼠纹状体神经元亚群中的Ca(2+)。丁丙诺啡的作用主要被纳洛酮（一种非选择性阿片受体拮抗剂）所削弱，但不受 μ、κ、δ 或 NOP 选择性拮抗剂的影响。β-内啡肽（0.1 μM）增加Ca(2+)的幅度和速度比丁丙诺啡低。与丁丙诺啡相似，β-内啡肽的作用也明显被纳洛酮削弱，但不受阿片类选择性拮抗剂的影响。吗啡（0.1-10 μM）对纹状体神经元中的Ca(2+)没有影响。
我们的结果表明，丁丙诺啡和β-内啡肽作用于大鼠纹状体神经元上的一种独特类型/亚型的质膜阿片受体，或激活细胞内阿片样受体。
