[Morphogenesis of thoracic aorta aneurysms: investigation of matrix metalloproteinases and their tissue inhibitors].

The matrix metalloproteinases are a large group of proteases with a central role of the degradation of all types of extracellular matrix. The present study investigated expression of matrix metalloproteinases (MMP-1, -2, -9) and their inhibitors (TIMP-1, -2) in chronic Aneurysm of the Thoracic Aorta (ATA) and Post-Stenotic Dilatation of the ascending aorta due to valvular aortic stenosis (PSD). Fragments of the ascending aorta that had been taken from the patients during coronary by-pass surgery were used as controls. Immunohistochemical investigation showed that medical SMC in the samples taken from aortas with ATA and PDS expressed a stronger immunoreactivity for MMP-1, -2, -9 and TIMP-1, -2 as compared to controls. It can be suggested that during formation of ATA and PSD, production of MMPs and TIMPS by medial smooth muscle cells is of great importance.