Uptake and degradation of Curosurf® after tracheal administration to newborn and adult rabbits

This paper examines the removal from the airways of Curosurf®, a commercial surfactant derived from porcine lungs, administered at pharmacological concentrations to newborn or adult animals. Curosurf was labelled by the addition of radioactive dipalmitoyl phosphatidylcholine (DPPC) and administered intratracheally to newborn and adult rabbits at a dose of 200 mg·kg-1 body weight. The disappearance of DPPC from the airways and its appearance in alveolar macrophages, lung parenchyma, lamellar bodies, serum, liver, kidneys and brain was then studied for 24-48 h. The in vitro degradation of Curosurf DPPC by alveolar macrophages was also studied. During the first 3 h after instillation, large amounts of Curosurf left the airways and became associated with tissue, indicating that it mixed rapidly with the endogenous pools of surfactant. A fraction of administered DPPC became associated with the lamellar bodies, suggesting that Curosurf can be recycled. Curosurf administration did not stop th...