Incorporation in vitro of 14C-labelled acetate and 32P-labelled phosphate into lipid in thoracic aortae from hypertensive and nomotensive rabbits.

The effect of prior hypertension on lipid synthesis in the thoracic aortae of normal-fed and cholesterol-fed rabbits was studied in vitro using[1(-14)C] acetate and [32P] phosphate as lipid precursors. In normally fed rabbits, prior hypertension did not increase the incorporation of the labelled precursors into either phospholipid or neutral lipid. In cholesterol-fed rabbits, hypertension increased the incorporation of [32P] phosphate into phosphatidyl-choline and of [1(-14)C-acetate into cholesterol ester. The increased incorporation of [1(-14)C] acetate into cholesterol ester was accompanied by an increase in intimal total cholesterol concentration. For both normotensive and hypertensive cholesterol-fed rabbits there was a close correlation between cholesterol esterification and total cholesterol concentration of the thoracic intima. It is concluded that the increase in aortic lipid synthesis in hypertensive cholesterol-fed rabbits is secondary to the increased cholesterol accumulation induced by hypertension rather than to a direct stimulation of arterial wall lipid synthesis by hypertension per se.