PHARMACOLOGICAL HETEROGENEITY OF HUMAN LUNG AND COLON CELLS - EFFECT OF TERFENADINE AND CETIRIZINE

H-1-blockers may have antiallergic properties which cause the blocking of eicosanoid release, and the effect of these drugs may differ accor ding to the phenotype of mast cells. This study examined the ability o f terfenadine and cetirizine to inhibit the release of arachidonic aci d-derived mediators from human lung and colon cells. Dispersed cells w ere challenged with anti-IgE in the presence or absence of 10 mu M of terfenadine or cetirizine, and the release of prostaglandin (PG)D-2 an d leukotriene (LT)C-4/D-4 was assessed by enzyme immunoassay (EIA). Te rfenadine caused significant inhibition of both PGD(2) and LTC(4)/D-4 (49+/-9 and 29+/-19%, respectively) from human lung cells but had a le ss marked effect on PGD(2) release from human colon cells (21+/-9% for PGD(2) and 18+/-9% for LTC(4)/D-4). In contrast, although cetirizine caused significant inhibition of both mediators measured in lung cells (38+/-16% for PGD(2) and 34+/-19% for LTC(4)), it did not cause any s ignificant inhibition of either mediator from human colon cells. These findings suggest that H-1-antagonists may have additional properties, and the differential effects of cetirizine on lung and colon tissue m ay indicate differences in mast cell phenotype.