[Bronchial hyperresponsiveness to histamine induced by intravenous administration of 9 alpha,11 beta-prostaglandin F2 (9 alpha,11 beta-PGF2) in guinea pigs].

The effects of intravenous administration of 9 alpha,11 beta-PGF2, a stable metabolite of prostaglandin D2 (PGD2), on bronchial smooth muscle in guinea pigs were investigated by measurement of dynamic compliance and dynamic respiratory resistance using a formula to exclude the effects of differences in airway wall thickness. With this formula, the ratio of bronchial smooth muscle constriction by histamine can be estimated as an index of bronchial hyperresponsiveness to histamine. Administration of 9 alpha,11 beta-PGF2 induced airway wall edema. The ratio of bronchial smooth muscle constriction by histamine was significantly enhanced by the administration of 9 alpha,11 beta-PGF2a. TXA2 antagonists, ONO-NT-128 and ONO-8809, inhibited the effect of 9 alpha,11 beta-PGF2 administration. These results suggest that 9 alpha,11 beta-PGF2 act as important mediators affecting bronchial hyperresponsiveness, and TXA2 may play a role in 9 alpha,11 beta-PGF2-induced airway wall edema and bronchial hyperresponsiveness to histamine.