Characteristics of pertechnetate movement across the canine tracheal epithelium.

Several 99mTechnetium-labeled markers have been used to study the barrier properties of the pulmonary epithelium; among these compounds is sodium pertechnetate (TcO4-). As TcO4- has pseudohalide properties, and as the characteristics of the movement of this ion across the airway epithelium are unknown, we examined its bidirectional permeability coefficients, and compared them with those of radiolabeled Cl- and mannitol in canine tracheal epithelium in vitro. We found that this ion behaves similarly to Cl- in its translocation across the airway epithelium.