1. [3H]morphine binding is enhanced by IL-1-stimulated thymocyte proliferation.
- Author
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Roy S, Ge BL, Ramakrishnan S, Lee NM, and Loh HH
- Subjects
- Animals, Cell Division, Feedback, Mice, Mice, Inbred ICR, Phytohemagglutinins pharmacology, Receptors, Opioid physiology, T-Lymphocytes cytology, Tetradecanoylphorbol Acetate pharmacology, Interleukin-1 pharmacology, Lymphocyte Activation, Morphine metabolism, T-Lymphocytes metabolism
- Abstract
Mouse thymocytes incubated in vitro with increasing concentrations of interleukin-1 (IL-1) in the presence of phytohemagglutinin (PHA) exhibited a dose-dependent increase in cell proliferation, as measured by [3H]thymidine incorporation. Under these conditions, there was a parallel dose-dependent increase in specific [3H]morphine binding, with a maximum increase of approximately 5-fold over basal levels. The binding sites differ from classical opioid receptors in that they are not stereo-selective. Interleukin-2 was ineffective in promoting either cell proliferation or enhanced opioid binding, but the effects of IL-1 could be mimicked by phorbol myristate acetate (PMA), suggesting the involvement of tyrosine phosphorylation. These results indicate that morphine-binding sites on immune cells can be regulated by cytokine activation.
- Published
- 1991
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