AFFINITY OF LOW-DENSITY LIPOPROTEINS FOR AN ARTERIAL MACROMOLECULAR COMPLEX - STUDY IN ISCHEMIC HEART-DISEASE AND CONTROLS

Levels of serum cholesterol, triglycerides, lipoprotein pattern and the insolubilization of serum low density lipoproteins (LDL, .beta.-lipoprotein) by a factor present in arterial intima.sbd.media extracts was investigated in 55 patients with acute coronary heart disease and 50 healthy controls. In blood samples obtained 24 h after the episode, the serum .beta.-lipoproteins from male normotensive patients showed a high tendency to precipitate when incubated with the intima-media extracts, nearly twice the value measured in the control group. This affinity returned almost to control level after 21 days in the hospital. Hypertensive patients showed a serum cholesterol higher than the controls but almost no difference in LDL-arterial factor interaction. The composition of isolated LDL was studied in 7 patients and 8 controls; the total cholesterol/protein plus phospholipid ratio had a positive exponential correlation with the lipoprotein-arterial factor affinity. The results of LDL analyses suggest that a change in their composition, frequent in normotensive patients, can lead to an increased affinity of this lipoprotein for arterial intima-media components. This process could be an additional risk factor contributing to the deposition of LDL in the arterial wall.