Hispidulin, a natural flavone, inhibits human platelet aggregation by increasing cAMP levels.

Hispidulin, a natural flavone, and theophylline inhibited platelet aggregation triggered by adenosine-5'-monophosphate, arachidonic acid, paf-acether and collagen. Hispidulin was 100-fold more potent than theophylline. A threshold concentration of PGE1 did not modify the anti-aggregatory effect of hispidulin but potentiated the effect of theophylline.

Relaxation of isolated human pulmonary muscle preparations with prostacyclin (PGI2) and its analogs.

The effects of PGI2 and two analogs Iloprost and ZK 96480 were examined on isolated human pulmonary muscle preparations. High concentrations of these agents reduced the basal tone in all types of preparations. In addition, they relaxed tissues which had been maximally contracted with histamine (50 microM).

Effects of various pharmacological agents on isolated human bronchial and pulmonary arterial and venous muscle preparations contracted by leukotriene D4.

The response of isolated human bronchial muscle preparations to leukotriene D4 (LTD4, 0.1 microM; 0.22 +/- 0.