Tolbutamide effect on cultured human endothelial cells with special reference to platelet aggregation

Since the UGDP report, there have been many discussions on tolbutamide in relation to arterial metabolism. In view of this, we investigated the effect of tolbutamide on endothelial cells using ADP-induced platelet aggregation. We followed Gimbrone's method of cell culture and after the addition of tolbutamide, a platelet aggregation test was performed. 100 microM tolbutamide showed no inhibitory effect on platelet aggregation, but 1 mM tolbutamide effected a 25% decrease in aggregation. These results suggest that tolbutamide does not inhibit prostacyclin synthesis of endothelial cells at conventional dosages.