[Physiological properties of the blood vessel smooth muscles in experimental atherosclerosis]

The contraction of smooth muscle cells in response to the effect of catecholamines and potassium chloride was studied in experiments on isolated ring segments of the rabbit aorta under normal conditions and in experimental cholesterol atherosclerosis at its early developmental stages. It was found that at the early stages of atherosclerosis development the character of the contractile reactions was marked by changes which may be considered from the standpoint of disorder in the ion mechanisms of the interrelationships of sodium and calcium both on the membrane and within the smooth muscle cell, and from the standpoint of increased reactivity of chemically sensitive calcium channels of the membrane. The cause of these changes may be the accumulation of cholesterol, lipoproteins and acid mucopolysaccharides in the vascular wall at the early stages of atherosclerosis development.