Abstract
It is now known that antiprotease (protease inhibitor) exists in the nasal and tracheobronchial secretion, and such antiprotease activity decreases in acute inflammation. The present study was undertaken to clarify protease activity of tnacheobronchial secretion of rats. Protease activity measured was fibrinolytic activity using the fibrin plate method. The tracheobronchial fluid was collected from the tracheal lumen through the tracheostoma after performing the infusion of the physiological saline into the lumen and its simultaneous suction using the automatic infusion pump. The secretion obtained showed marked fibrinolytic activity in the standard fibrin plate. In the plasminogen free fibrin plate or t-AMCHA containing fibrin plate, no fibrinolytic activity was observed. Therefore, it is evident that fibrinolytic activity measured was due to the plasminogen activator activity. The gel filtration by sephadex G-50 after partial purification by ammonium sulfate showed two peaks, indicating the existence of two different activators (high and low molecular weights).
