Korean J Physiol Pharmacol.
1998 Dec;2(6):671-676.
Effects of dopamine and haloperidol on morphine-induced CREB and AP-1 DNA binding activities in differentiated SH-SY5Y human neuroblastoma cells
- Affiliations
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- 1Department of Pharmacology and Institute for Medical Science, Keimyung University School of Medicine, Taegu 700-712, Korea.
Abstract
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In the present study, we first examined whether the changes in the DNA
binding activities of the transcription factors, cAMP response element
binding protein (CREB) and activator protein-1 (AP-1) mediate the
long-term effects of morphine in differentiated SH-SY5Y human
neuroblastoma cells. The increases in CREB and AP-1 DNA binding
activities were time-dependent up to 6 days of morphine treatment (1,
4, and 6 days). However, the significant reduction in the DNA binding
activities of CREB and AP-1 was observed after 10 days of chronic
morphine (10 muM) administration. Secondly, we examined whether the
changes of CREB and AP-1 DNA binding activities could be modulated by
dopamine and haloperidol. Dopamine cotreatment moderately increased the
levels of the CREB and AP-1 DNA binding activities induced by 10 days
of chronic morphine treatment, and haloperidol cotreatment also
resulted in a moderate increase of the CREB and AP-1 DNA binding
activities. However, dopamine or haloperidol only treatment showed a
significant increase or decrease of the CREB and AP-1 DNA binding
activities, respectively. In the case of acute morphine treatment, the
CREB and AP-1 DNA binding activities were shown to decrease in a
time-dependent manner (30, 60, 90, and 120 min). Taken these together,
in differentiated SH-SY5Y cells, morphine tolerance seems to involve
simultaneous changes of the CREB and AP-1 DNA binding activities. Our
data also suggest the possible involvement of haloperidol in prevention
or reversal of morphine tolerance at the transcriptional level.