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


METHODS
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.


RESULTS
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.


CONCLUSIONS
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.
Gao
Can
C
Shanghai Institute of Materia Medica, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China.
Chen
Li-Wei
LW
Tao
Yi-Min
YM
Chen
Jie
J
Xu
Xue-Jun
XJ
Chi
Zhi-Qiang
ZQ
D000700:Analgesics / Q000494:pharmacology; D000818:Animals; D002478:Cells, Cultured; D000242:Cyclic AMP / Q000378:metabolism; D017362:Cyclic AMP Response Element-Binding Protein / Q000378:metabolism*; D005283:Fentanyl / Q000031:analogs & derivatives* / Q000494:pharmacology*; D006624:Hippocampus / Q000166:cytology*; D009020:Morphine / Q000494:pharmacology; D009270:Naloxone / Q000494:pharmacology; D009474:Neurons / Q000187:drug effects* / Q000378:metabolism; D010766:Phosphorylation / Q000187:drug effects; D051381:Rats; D017207:Rats, Sprague-Dawley; D017450:Receptors, Opioid, mu / Q000378:metabolism; D015398:Signal Transduction; D013237:Stereoisomerism
D000700:Analgesics; D017362:Cyclic AMP Response Element-Binding Protein; D017450:Receptors, Opioid, mu; D009270:Naloxone; D009020:Morphine; C037016:F 7302; D000242:Cyclic AMP; D005283:Fentanyl