Abstract: | Thromboxane B2, 6-keto-Prostaglandin F1 alpha, and Prostaglandin E2 release have been quantitated from cultured adult bovine endothelial cell monolayers and from ex Vivo vascular segments employing specific radioimmunoassays and thin layer chromatography. Release of all three prostaglandins was demonstrable from both endothelial cell systems under basal conditions and following exposure to the ionophore A23187 and arachidonic acid. In culture, the quantity of 6-keto-PGF1 alpha released was diminished compared to amounts released from the vessel segments while thromboxane B2 and prostaglandin E2 release were similar in the two endothelial model systems. However, the amount of thromboxane B2 assayed was small and the quantity of thromboxane A2 it represents is probably of little in vivo significance compared to prostacyclin. |