Cathepsin A activity of a parietal thrombus of an abdominal aortic aneurysm

We evaluated the cathepsin A activity of a parietal thrombus of an abdominal aortic aneurysm. We compared this activity to that of a retracted blood clot homogenate. Cathepsin A of aneurysm parietal thrombus homogenate and blood clot homogenate showed the highest activity on Z–Phe–Ala. It was lower on Z–Phe–Phe, Z–Glu–Tyr, Z–Glu–Phe, Z–Gly–Phe, and the lowest activity was on Z–Gly–Ala. We conclude that cathepsin A’s activity on a parietal thrombus of an aneurysm is much higher than blood clot cathepsin A activity. (Folia Histochemica et Cytobiologica 2011; Vol. 49, No. 1, pp. 10–12)