Comparison of the modulatory effect of ketotifen, sodium cromoglycate, procaterol and salbutamol in human skin, lung and tonsil mast cells.

To assess the influence of mast cell heterogeneity on the inhibition of mediator release by drugs, the effects of ketotifen, sodium cromoglycate and beta-adrenoceptor agonists were examined against IgE-dependent histamine and prostaglandin D2 release from enzymatically dispersed human skin, lung and tonsillar mast cells. At high concentrations, ketotifen was an inhibitor of histamine and prostaglandin D2 release from lung and tonsillar mast cells. No cross-tachyphylaxis with sodium cromoglycate was seen. In skin mast cells no inhibition of mediator release was observed with 1.0 microM ketotifen, above which histamine release was induced. Sodium cromoglycate was a weak inhibitor of histamine and prostaglandin D2 release from lung and tonsillar mast cells and showed tachyphylaxis. Sodium cromoglycate did not inhibit histamine and prostaglandin D2 release from skin mast cells. On the other hand, no heterogeneity was observed with the beta-adrenoceptor agonists, procaterol and salbutamol. beta-Adrenoceptor stimulants were significantly more effective in inhibiting prostaglandin D2 than histamine release. No tachyphylaxis was seen with prolongation of the incubation time before challenge. Our results suggest that human mast cells are heterogeneous with respect to the modulation of mediator release by ketotifen and sodium cromoglycate but not beta-adrenoceptor agonists.