Vasoactive intestinal peptide enhances phorbol myristate acetate-induced chemiluminescence in human lymphocytes. |
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| Authors: | M A Lopez-Gonzalez J M Guerrero M Lucas |
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| Affiliation: | Departamento de Bioquímica Médica y Biología Molecular, Hospital Universitario Virgen Macarena, Facultad de Medicina, Sevilla, Spain. |
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| Abstract: | Phorbol-myristate-acetate (PMA) induced in lymphocytes the production or reactive oxygen intermediates in a process which was stimulated by the presence of vasoactive intestinal peptide (VIP) in a dose-dependent response at VIP concentrations in the range 10(-11)-10(-8) M. The dissociation constant for the high-affinity receptors of VIP agreed with the ID50 of the activation of adenylate cyclase, and the ID50 for the stimulation by VIP of PMA-induced chemiluminescence, which were close to 0.2 nM VIP. Forskolin produced in lymphocytes an effect quite similar to VIP. A comparison of the response to VIP and forskolin of lymphocytes and monocytes showed that, in contrast to forskolin, VIP failed to induce the above described effect in monocytes. A possible mechanism involving protein kinase C, which is activated by PMA, and an intracellular signal linked to VIP receptors is pointed out. This study further supports a role for VIP as a mediator in the neuroimmune system. |
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