[Bronchial hyperresponsiveness to histamine induced by intravenous administration of prostaglandin D2 (PGD2) in guinea pigs].

Prostaglandin D2 (PGD2) and thromboxane A2 (TXA2) have been suggested to play important roles in the pathogenesis of bronchial asthma. In the present study, effects of i.v.-administration of PGD2 on bronchial hyperresponsiveness in guinea pigs were investigated by the measurement of dynamic compliance and dynamic respiratory resistance with formulae which can exclude the effects of changes of the airway wall thickness. With these formulae, the ratio of bronchial smooth muscle constriction by histamine can be estimated as an index of bronchial hyperresponsiveness. Administration of PGD2 induced airway wall edema. The ratio of bronchial smooth muscle constriction by histamine was enhanced with the administration of PGD2. Moreover, TXA2 antagonists, ONO-NT-126 and ONO-8809, inhibited the effect of PGD2 administration.