| pubmed-article:2962515 | pubmed:abstractText | To study the control of histamine release, we developed techniques for culturing fundic mucosal mast cells. After enzyme dispersion, enrichment by elutriation, and overnight suspension culture, mast cells accounted for 30% of the cells present. Histamine release into the medium, measured by radioenzymatic assay, was stimulated by the lectin concanavalin A (Con A). Ragweed antigen released histamine in antisera-sensitized cultures. Con A-induced histamine release was enhanced by adenosine, but adenosine alone was inactive. The relative potency of adenosine analogues was consistent with interaction at an adenosine A1-receptor site. The calcium ionophore A23187 (0.1-1 microM) also induced histamine release. Phorbol esters that activate protein kinase C, such as phorbol 12-myristate 13-acetate, did not release histamine but enhanced release when added to low concentrations of A23187. In contrast, inactive phorbols, such as 4 alpha-phorbol 12,13-didecanoate, failed to enhance A23187-induced release. Parallel studies with canine hepatic mast cells yielded comparable results. We conclude that canine fundic mast cells possess receptors for immunoglobulin E and adenosine. Our data are consistent with increases in cytosolic calcium and protein kinase C activation working synergistically to stimulate fundic mast cells. | lld:pubmed |
