A-MU-RECEPTOR OPIOID AGONIST INDUCES AP-1 AND NF-KAPPA-B TRANSCRIPTION FACTOR ACTIVITY IN PRIMARY CULTURES OF RAT CORTICAL-NEURONS

Activator protein 1 (AP-1) and nuclear factor kappa B (NF-kappa B) rep resent mammalian transcription factors which bind to distinct enhancer motifs. The specific mu-receptor opioid agonist, Tyr, D-Ala(2), Gly, N-Me-Phe(4), Gly-ol(5) (DAMGO), was found to increase AP-1 and NF-kapp a B activity in primary cultures of neurons from rat cerebral cortex. Acute (2 h, 4 h) and long-term (72 h) treatment with DAMGO time-depend ently increased the DNA-binding activity of both AP-1 and NF-kappa B a nd the stimulation could be abolished or inhibited by concurrent incub ation with naloxone. However, acute naloxone-precipitated withdrawal d id not significantly change AP-1 or NF-kappa B activity. These results indicate a mu-opioid receptor-related co-induction of AP-1 and NF-kap pa B transcription factors in cultured cortical neurons.