The contractile response of the normal and atherosclerotic aortic strips to noradrenaline, and potassium ions.

In order to explain whether the arterial smooth muscle exhibits altered contractile properties in atherosclerosis, normal and atherosclerotic rabbit aortic strips were exposed to noradrenaline (NA) and potassium chloride (KCl). The experiments were repeated with normal blood and the containing an excess of free fatty acids (FFA) added to the bath. Contraction induced by NA was markedly enhanced in the atherosclerotic trips. In contrast the response of atherosclerotic aorta strips to KCl was reduced. Excess FFA blood added to the bath with NA normalized the previously enhanced contractile response in atherosclerotic aortic strips. An opposite change in KCl induced contraction was observed under the some conditions namely increased response occurred. We conclude that the enhanced reaction of atherosclerotic aortic strips to NA depending on a specific mechanism might be reversed by elevation of FFA in blood.