Relations between metabolic increase of plasma free fatty acids and the occurrence of arteriosclerotic thromboarteritis in rabbits.

Rabbits maintained for several weeks on a regimen of modest amounts of vitamin D and dietary cholesterol were placed in three groups in accordance with their response to repeated subcutaneous injections of nicotine in mineral oil. The group that had the greatest increase in plasma FFA following nicotine injections gradually developed, over a period of about 12 weeks, severe calcific atheroarteriosclerosis with peripheral thromboarteritis. Those that had a moderate increase in plasma FFA following nicotine injections developed calcific atheroarteriosclerosis but no thromboarteritis. Those that had the least increase in plasma FFA following nicotine injections developed no arterial lesions. Comparable or much greater increases in plasma FFA occurred in rabbits on the vitamin D-cholesterol regimen when adrenalin, ACTH or heparin was injected rather than nicotine. These animals did not develop calcific atheroarteriosclerotic thromboarteritis or any other lesions which could be correlated with the increased levels of plasma FFA. Inasmuch as nicotine, vitamin D or dietary cholesterol in the amounts used were innocuous when used alone, the interactions between the effects of at least these three factors need to be known in individual animals before the pathogenesis of the calcific atheroarteriosclerotic lesions with thrombosis can eventually be understood.