Chronic morphine treatment increases stimulatory beta-2 adrenoceptor signaling in A431 cells stably expressing the mu opioid receptor.

@article{Ammer1997ChronicMT,
  title={Chronic morphine treatment increases stimulatory beta-2 adrenoceptor signaling in A431 cells stably expressing the mu opioid receptor.},
  author={Hermann Ammer and R{\"u}diger Schulz},
  journal={The Journal of pharmacology and experimental therapeutics},
  year={1997},
  volume={280 1},
  pages={512-20}
}
Chronic opioid regulation of stimulatory beta-2 adrenoceptor (beta-2 AR) signaling was investigated in human mammary epidermoid carcinoma A431 cells stably expressing the cloned rat mu opioid receptor. In the cell clone used (A431/mu 13; Bmax = 302.9 +/- 46 fmol/mg membrane protein), the addition of morphine acutely attenuated basal as well as (-)-isoproterenol-stimulated cAMP accumulation. Prolonged exposure of the cells to morphine (10 microM; 2 d) resulted in homologous desensitization of… CONTINUE READING