Human aortic elastin from normal individuals and atherosclerotic patients: lipid and cation contents; susceptibility to elastolysis.

Aortic elastins, isolated from 30 humans of different ages, were purified by alkaline extraction, and separated into two groups depending on the presence of atherosclerotic plaques and calcification (grades 0 and 1). It was confirmed that the severity of atherosclerosis increases significantly with age (P less than 0.001) and elastin content decreases with atherosclerosis (P less than 0.001). The hydrolysis of the aortic elastins using pancreatic porcine elastase (PPE) was studied. It was observed that increased elastolytic activities are connected with severity of atherosclerosis (P less than 0.001) and both Vm and Km apparent kinetic parameters are affected (P less than 0.001). Correlation tests have shown that enzymatic hydrolysis is significantly modified by cholesterol (P less than 0.05), calcium (P less than 0.001) and magnesium concentrations (P less than 0.01) but only cholesterol changes significantly Vm and Km parameters.