The effect of high insulin concentrations on prostacyclin production as measured by 6-keto PGF1 alpha determination

The effect of insulin in varied concentrations on the production of 6-keto PGF1 alpha, the metabolite of prostacyclin, by rat aortic tissue in vitro was assessed by radioimmunoassay. An insulin concentration of 50 microU/ml produced no change in 6-keto PGF1 alpha from the control samples, but concentrations of 100 microU/ml and 250 microU/ml reduced production from a control value of 0.326 +/- 0.031 ng/mg to 0.253 +/- .018 ng/mg (P less than .05) and 0.226 +/- 0.015 ng/mg (P less than .025) respectively. These results suggest that the suppression of PGI2 production may occur in states associated with insulin levels above those normally found in the postprandial state and might be one mechanism by which hyperinsulinemia might favor macrovascular disease.