The influence of lipoproteins (LDL and HDL) on PGI2-formation by isolated aortic preparations of rabbits

Abstract The influence of LDL- and HDL-concentrations of 0.5 – 2.0 mg/ml and 0.25 – 1.0 mg/ml respectively, from male and female donors on the formation of PGI 2 in isolated aortic preparations was investigated under in vitro conditions. LDL of male donors inhibited endogenous PGI 2 -formation and the conversion of exogenous PBH 2 to PGI 2 . On the other hand the highest concentration of HDL induced an increase in the basal and in the stimulated PGI 2 -formation. Lipoproteins of female donors showed no or only a weak stimulating effect on PGI 2 -formation. Human serum albumin in comparable concentrations of 1 – 50 mg/ml remained without influence. The importance of the results for cardiovascular diseases is discussed.