[Ginkgolides antagonizing some effects of platelet-activating factor in vitro].
The mixture of platelet-activating factor (PAF) and platelets produced significant contraction of guinea pigs' bronchus, while the contraction induced by PAF alone was mild relatively, the IC50 were 6.14 x 10(-7) mol/L and 6.32 x 10(-4) mol/L respectively. There was significant difference between these two groups (P < 0.05). When the platelets were pre-incubated with ginkgolides for 10 minutes in Tris-Tyrode's buffered saline, effects of the PAF and platelets mixture were significantly inhibited (P < 0.01). Exposure of guinea pigs' bronchus to PAF in vitro resulted in a loss of beta-adrenergic receptors and responses to isoproterenol, and this effect of PAF was prevented by prior incubation of the guinea pigs' bronchus with ginkgolides (P < 0.05). The results showed ginkgolides were a potent PAF antagonist.
Dong
J C
JC
Huashan Hospital, Shanghai Medical University.
Li
M
M
Shi
Z Y
ZY
D000818:Animals; D018927:Anti-Asthmatic Agents / Q000494:pharmacology*; D001980:Bronchi / Q000187:drug effects; D004224:Diterpenes; D046934:Ginkgolides; D006168:Guinea Pigs; D007783:Lactones / Q000494:pharmacology*; D009119:Muscle Contraction / Q000187:drug effects*; D009130:Muscle, Smooth / Q000187:drug effects*; D010972:Platelet Activating Factor / Q000037:antagonists & inhibitors*
D018927:Anti-Asthmatic Agents; D004224:Diterpenes; D046934:Ginkgolides; D007783:Lactones; D010972:Platelet Activating Factor; C045856:ginkgolide B