Human basophil/mast cell releasability. VII. Heterogeneity of the effect of adenosine on mediator secretion.

Abstract 5'-N-ethylcarboxamideadenosine (NECA) > 2-chloroadenosine > adenosine > N 6 -(R-phenyl-isopropyl)-adenosine (R-PIA) inhibited in vitro anti-IgE-induced histamine and peptide leukotriene C 4 (LTC 4 ) release from human basophils in a concentration- dependent fashion. Micromolar concentrations of adenosine, NECA and R-PIA potentiated the anti-IgE-stimulated release of histamine and LTC 4 from human lung parenchymal mast cells. Submillimolar concentrations of adenosine, NECA and R-PIA inhibited in a concentration dependent manner the release of histamine and prostaglandin D 2 (PGD 2 ) from skin mast cells challenged with anti-IgE. These results demonstrate marked heterogeneity of the modulatory effect exerted by adenosine on mediator release from human basophils and mast cells.