The effect of contraceptive steroids on the incorporation of U14C-glucose into porcine aortic lipids.

The in vitro effect of 17 alpha-ethinylestradiol (E) and/or medroxy progesterone acetate (P) was determined on their abilities to alter conversion of glucose to lipid by porcine aorta. The combination of steroidal agents EP/HI (combination at high concentration) at a concentration of 9.5 X 10(-9) moles/ml caused a significant (p less than 0.01) reduction in 14C incorporation into total lipid. When the concentration of each hormone was reduced by one-half EP/LO (combination at low concentration) to give a final concentration of 4.8 X 10(-9) moles/ml the incorporation was also significantly reduced (p less than 0.05). The aforementioned reductions were subsequently found to be the result of depressed incorporation of the substrate glucose for the synthesis of phospholipid (PL), triacylglyceride (TG), a combined fraction of free cholesterol, diacylglyceride and free fatty acid (FC+DG+FFA), and cholesteryl ester (CE). The hormones individually had no effect on the incorporation of U14C-glucose into lipid. The study suggests that these oral contraceptives, when administered in pharmacological doses, can depress the conversion of glucose into arterial wall lipid.