PRIMING EFFECT OF VASOACTIVE-INTESTINAL-PEPTIDE ON THE RESPIRATORY BURST OF NEUTROPHILS NON-MEDIATED BY PLASMA-MEMBRANE RECEPTORS

Vasoactive intestinal peptide (VIP) primed the respiratory burst of hu man neutrophils in response to phorbol myristate acetate. Maximal and half-maximal effects were achieved at 10 and 0.5 nM VIP respectively. The absence of plasma membrane receptors to VIP in neutrophils suggest s that priming of the respiratory burst should be considered as a side effect of VIP. However, from the above indicated concentration range, the priming of the neutrophil by VIP cannot be considered as a pharma cological effect. The enhancement of the formation of reactive oxygen metabolites by VIP may be important in the pathology of VIP-producing tissues.