Verapamil and the synthesis of prostacyclin in human veins

: The synthesis of the vasodilator prostacyclin (PGI2) depends on the intracellular calcium concentration. For this reason the purpose of this study was to document the effects of verapamil (1), a slow calcium channel blocking agent on venous tissue. Human varicose veins were studied which were removed by a stripping operation. The veins were investigated ex vivo and in vitro. For ex vivo studies 11 patients were given 0.01 g 1 i.v. during the operation. In vitro experiments were carried out by an addition of 22 mumol/l 1 to the incubate. The synthesis of PGI2 was studied according to the inhibition of the ADP induced platelet aggregation without and with addition of substrate (prostaglandin endoperoxide H2). 1 did not induce changes in the synthesis of PGI2, neither after administration to patients nor after addition to the incubation fluid compared to control vessels without addition of 1.