Effects of morphine on neurosteroidogenesis of primary cultured rat cerebral cortical neurons / 中国药理学通报

ABSTRACT

Aim To investigate the effect and mechanism of action of chronic morphine treatment on the neurosteroidogensis of primary cultured rat cerebral cortical neurons(CCNs).Methods The effect of morphine on the production of pregnenolone(PREG),dehydroepiandrosterone(DHEA),allopregnanolone(AP),pregnenlolone sulfate(PS)and dehydroepiandrosterone sulfate(DS)in cell culture media was measured by solid-phase extraction and LC-MS,with methyltestosterone(MT)or estrogen sulfate(ES)as internal standards.The dependence-like changes of CCNs were determined by testing the p-CREB level in the nuclear lysates using western blot.Results Compared with the control group,morphine treatment significantly reduced levels of PREG and DS respectively;opioid agonist DAMGO significantly reduced levels of PREG,DS and PS respectively,and increased the level of AP significantly.Compared with the morphine group,?-opioid-antagonist CTAP concomitant with morphine increased the level of PREG significantly.Compared with the control group,chronic morphine treatment or DAMGO treatment significantly increased the level of p-CREB in the CCNs.Compared with the morphine treatment group,?-antagonsit CTAP significantly reduced the level of p-CREB.Conclusion ?-opioid receptor mediated the inhibitory effect of morphine on levels of neurosteroids,and changes of neurosteroid levels might be related to morphine dependence.