Research Article Open Access

Selective Lymphocyte Activation and Inhibition of In Vitro Tumor Cell Growth by Novel Morphinans

Ricardo Gomez-Flores1, Kimberly R. Vietti2, William J. Dunn3, Reyes Tamez-Guerra1 and Richard J. Weber1
  • 1 Universidad Autónoma de Nuevo León, Mexico
  • 2 University of Illinois College of Medicine, United States
  • 3 University of Illinois College of Pharmacy, United States


Opioids can suppress immune functions and increase susceptibility to developing cancer and infectious diseases. Recently, novel opioid compounds have been synthesized that lack immunosuppressive effects. We evaluated the effects of morphinans with substituted pyrimidine (methyl, phenyl, hydroxy, and amino groups) and pyrazole groups on in vitro rat thymic lymphocyte and splenic macrophage functions, and tumor cell growth. We observed that morphinans with methyl, phenyl, hydroxy, amino, and pyrazole groups at concentrations from 10-10M to 10-5M plus Con A (2.5 mg/ml) significantly (P < 0.01) induced 2- to 2.9-, 2.3- to 6.4-, 2.4- to 3.4-, 2.6- to 3.4-, and 2.6- to 3.2- fold increases respectively in thymic lymphoproliferation compared with Con A alone; this effect was reversed by naloxone. Macrophage nitric oxide production was not altered by morphinans. In addition, we observed that all tested morphinans were associated with significant (P < 0.01) in vitro tumor cell growth inhibition of J774A (18-41%), L929 (12-36%), L5178 (9-15%) cell lines in a dose-dependent manner, at doses ranging from 10-11M to 10-5M. Morphinans may be applied in clinical situations where immunosuppression is undesirable.

American Journal of Immunology
Volume 2 No. 1, 2006, 1-7


Submitted On: 27 March 2006 Published On: 5 March 2005

How to Cite: Gomez-Flores, R., Vietti, K. R., Dunn, W. J., Tamez-Guerra, R. & Weber, R. J. (2006). Selective Lymphocyte Activation and Inhibition of In Vitro Tumor Cell Growth by Novel Morphinans. American Journal of Immunology, 2(1), 1-7.

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  • Rodent
  • spleen
  • thymus
  • monocytes/macrophages
  • T lymphocytes
  • nitric oxide
  • tumor immunity