Regulation of the prostacyclin synthetase activity by lipids

Association between total cholesterol and plasma thromboxane B2 in human adults

Apparently healthy adults were examined for their lipid and thromboxane parameters. The correlation between the levels of total cholesterol in serum and thromboxane B2/TXB2/ in plasma was strong mainly in men (p less than 0.01). However, the association between atherogenic index /AI/ and TXB2 levels tended to be higher in women. The authors suggest that, in healthy adults, elevated cholesterol levels coexist with abnormalities in thromboxane metabolism.

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

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 PGI2 in isolated aortic preparations was investigated under in vitro conditions. LDL of male donors inhibited endogenous PGI2-formation and the conversion of exogenous PBH2 to PGI2. On the other hand the highest concentration of HDL induced an increase in the basal and in the stimulated PGI2-formation. Lipoproteins of female donors showed no or only a weak stimulating effect on PGI2-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.