Effects of ohmefentanyl stereoisomers on phosphorylation of cAMP- response element binding protein in cultured rat hippocampal neurons

• Published in: Acta pharmacologica Sinica Vol. 24; no. 12; pp. 1253 - 1258
• Main Authors: Gao, Can, Chen, Li-Wei, Tao, Yi-Min, Chen, Jie, Xu, Xue-Jun, Chi, Zhi-Qiang
• Format: Journal Article
• Language: English
• Published: United States 01.12.2003
• Subjects: Analgesics - pharmacology; Animals; Cells, Cultured; Cyclic AMP - metabolism; Cyclic AMP Response Element-Binding Protein - metabolism; Fentanyl - analogs & derivatives; Fentanyl - pharmacology; Hippocampus - cytology; Morphine - pharmacology; Naloxone - pharmacology; Neurons - drug effects; Neurons - metabolism; Phosphorylation - drug effects; Rats; Rats, Sprague-Dawley; Receptors, Opioid, mu - metabolism; Signal Transduction; Stereoisomerism
• ISSN: 1671-4083

To define the effects and signal pathways of ohmefentanyl stereoisomers [(-)-cis-(3R,4S,2'R) OMF (F9202), (+)-cis-(3R,4S,2'S) OMF (F9204), and (-)-cis-(3S,4S,2'R) OMF (F9203)] on the phosphorylation of cAMP-response element binding protein (CREB) in cultured rat hippocampal neurons. The effects of the three OMF stereoisomers and morphine (Mor) on cAMP accumulation and CREB phosphorylation were monitored by radioimmunoassay and Western blot analysis, respectively. The three OMF stereoisomers and Mor could all partially inhibit forskolin-stimulated (25 micromol/L, 15 min) cAMP accumulation in a dose-dependent manner and this effect could be reversed by naloxone. F9202, F9204, and Mor could significantly increase CREB phosphorylation from 2.88 to 3.59 folds over control levels after 30-min exposure. This effect was reversed by naloxone, but F9203 failed to increase CREB phosphorylation. KN-62 and staurosporine significantly blocked the opioids- induced CREB phosphorylation, while H-89 and PD 98059 had no effect on the actions. Mor, F9202, and F9204, which could induce psychological dependence affected via the micro-opioid receptor, stimulated intracellular signal pathways involving Ca2+/calmodulin-dependent protein kinases (CCDPK) and protein kinase C (PKC) pathways, which in turn initiated CREB phosphorylation. F9203, which could not induce dependence, had no effect on CREB phosphorylation in hippocampal neurons. The increased CREB phosphorylation in hippocampal neurons may play a role in opioids dependence.