Prostaglandins and endothelial stability.

A series of prostaglandin derivatives has been investigated in the model of circulating endothelial cells in rats with or without provocation by citrate. Both PGI2 and PGF2 alpha have been effective in fractions of pg/kg, the former showing a protective and the latter a destabilizing activity. Most derivatives have a very complicated dose-effect curve over a wide range of doses, caused possibly by various metabolites exceeding activity thresholds with growing doses.