Influence of indometacin administered in vivo on the synthesis of PGI2-like substances in human veins.

: The effect of the cycloocygenase inhibitor indometacin (Indo) on the synthesis of prostacyclin-like substances (PGI2-LS) in human veins has been studied after in vivo and in vitro application of the drug. PGI2-LS were bioassayed by ADP-induced platelet aggregation during twenty minutes incubation time. We used human veins of varicose patients, which were removed during stripping operations. Indo was applied by rectal application in vivo or added to the incubation fluid. The synthesis of PGI2-LS was inhibited by Indo in both experiments in a time dependent manner.