Effects of quercetin on aggregation and intracellular free calcium of platelets.
OBJECTIVE
To study the effects of Que on the intraplatelet free calcium concentration and the effects of calcium on the inhibition of platelet aggregation by Que.


METHODS
Using Quin-2 fluorescence technique.


RESULTS
Que inhibited the platelet aggregation and the rise of [Ca2+]i induced by thrombin in platelets. The values of IC50 and 95% confidence interval were 146.2 (92.4 - 231.3) and 78.5 (49.5 - 124.4) mumol.L-1, respectively. The inhibitory effects of Que on platelet aggregation induced by thrombin were reduced by adding calcium to the medium, and Que had no effect on thrombin-induced internal Ca2+ release from dense tubular system.


CONCLUSIONS
The inhibitory effects of Que on aggregation and the rise of [Ca2+]i in platelets was mainly due to an inhibition of Ca2+ influx.
Xiao
D
D
Department of Pharmacology, Suzhou Medical College, China.
Gu
Z L
ZL
Bai
J P
JP
Wang
Z
Z
D000328:Adult; D001693:Biological Transport, Active / Q000187:drug effects; D001792:Blood Platelets / Q000378:metabolism; D002118:Calcium / Q000097:blood*; D005260:Female; D006801:Humans; D008297:Male; D010974:Platelet Aggregation / Q000187:drug effects*; D010975:Platelet Aggregation Inhibitors / Q000494:pharmacology*; D011794:Quercetin / Q000494:pharmacology*; D013917:Thrombin / Q000037:antagonists & inhibitors; D013927:Thrombosis / Q000188:drug therapy*
D010975:Platelet Aggregation Inhibitors; D011794:Quercetin; D013917:Thrombin; D002118:Calcium