The sensitivity of guinea pig mesenteric and pulmonary mast cells to some histamine releasers.

The mesenteric and pulmonary mast cells of guinea pigs were obtained by enzymatic dispersion of the tissues with the enzyme collagenase. The guinea pig mast cells obtained by this method were morphologically intact, as judged by light microscopy. The mast cells from lung and mesentery of actively sensitized guinea pigs released histamine in a dose-dependent fashion after challenge with specific antigen. Both pulmonary and mesenteric mast cells of nonsensitized animals were unresponsive to the action of compound 48/80 and concanavalin A. Both populations of mast cells responded to polymyxin B, but the magnitude of histamine release was low. These cells responded strongly to the ionophore A23187; the mesenteric mast cells were markedly more reactive than pulmonary mast cells.