Stimulation of prostacyclin synthesis in rats treated with phenobarbital.

The effect of phenobarbital treatment on the synthesis of prostacyclin in coronary vascular microsomes was studied in Sprague Dawley rats. It was found that the treatment increased the synthesis of prostacyclin by nearly 100%. The treatment also resulted in an increase in HDL and a decrease in LDL in the serum. In vitro effects of HDL and LDL on the microsomal synthesis of prostacyclin showed that the synthesis was stimulated by HDL and inhibited by LDL. Hence it appears that the increase in prostacyclin synthesis resulting from phenobarbital treatment was at least partly due to increased level of HDL and decreased level of LDL in the serum.