TOBACCO-SMOKE RELEASES PREFORMED MEDIATORS FROM CANINE MAST-CELLS AND MODULATES PROSTAGLANDIN PRODUCTION

The role of an extract of tobacco smoke in activating mast cells was studied. With the use of isolated, canine mast cells as a model, we found that cigarette smoke solution (CSS) induced the release of the preformed mediators histamine and tryptase from these cells in an energy- and temperature-dependent, non-cytotoxic manner. There was no requirement for extracellular calcium. Nicotine tartrate did not reproduce the effect of CSS. Interestingly, mast cells produced little prostaglandin D2 (PGD2) in response to the CSS, and there was a concentration-related inhibition of calcium ionophore A23187-induced PGD2 synthesis. This suggests at least two mechanisms acting on the mast cell: tobacco smoke can directly activate mast cells to release preformed mediators and can simultaneously inhibit prostaglandin production. These observations suggest a mechanism by which mast cells may participate in the bronchospastic and proinflammatory changes seen in the lungs and airways of smokers.