Elastase-like enzymes in aortas and human breast carcinomas: quantitative variations with age and pathology.

Two neutral proteases have been isolated from aortas and human breast tumors. The aortic elastase-like enzyme has been further purified. The details of this purification procedure will be given and some of the properties of the purified enzyme (susceptibility to various kinds of substrates, degree of inhibition of serum inhibitors, alpha 1-antitrypsin and alpha 2-macroglobulin). This elastinolytic activity of the aorta increased with age and with the degree of atherosclerosis. Both parameters seem to act independently and in a cumulative fashion. Elastinolytic activity has been demonstrated in extracts of human breast carcinomas and is exponentially related to the age of the patient. There exists a parallel neosynthesis of elastin which increased also with the age of the patient. Some characteristics of the polymeric elastin isolated from the tumor tissue will be given. The possible role of this neutral protease present in human aortas and human breast carcinomas will be discussed.