Characterization of Purified Dog Mastocytoma Cells

There is conflicting evidence as to which autonomic receptors mast cells possess and whether the receptors are capable of modulating mediator release. We have studied dog mastocytoma cells because they are available in large numbers in a relatively pure form, unlike normal dog mast cells. Mastocytoma nodules from a dog were excised and disaggregated with collagenase to provide a cell suspension of mastocytoma cells of u003e 92% purity. The presence of autonomic receptors was assessed by both radioligand binding assays and by evaluating pharmacologic modulation of mediator release. In the radioligand binding assays, beta-adrenergic receptors were estimated by [3H]dihydroalprenolol binding, alpha-adrenergic receptors by [3H]prazosin binding and cholinergic receptors by [3H]quinuclidinyl benzilate binding. Nonspecific binding was determined in each case by incubation in the presence of the specific antagonists propranolol, phentolamine, and atropine, respectively. The effect of autonomic agonists on immunologic ...