Granular Pneumocytes: Electron Microscopic Evidence of Their Exocrinic Function

The contents of the lamelar bodies of granular pneumocytes are normally released into the alveolar lumen. Exposure of guinea pigs to an atmosphere containing carbon dioxide causes the formation of abnormal lamellar bodies and a significant increase in the pulmonary surface tension. The eventual return to a normal pulmonary surface tension coincides with the formation of normal lamellar bodies.