Particle deposition in the lung of the Göttingen minipig

• Published in: Inhalation toxicology 2010-08, Vol.22 (10), p.828-834
• Main Authors: Windt, Horst, Kock, Heiko, Runge, Frank, Hübel, Ulrich, Koch, Wolfgang
• Format: Article
• Language: English
• Subjects: Aerosols - pharmacokinetics; Animals; Bronchi - metabolism; Female; Lung - metabolism; Lung deposition; Metals, Rare Earth - pharmacokinetics; minipig; Models, Animal; Models, Biological; Nasal Mucosa - metabolism; Oxides - pharmacokinetics; particle; Particle Size; Particulate Matter - pharmacokinetics; Respiratory Function Tests - veterinary; Swine; Swine, Miniature - physiology; Trachea - metabolism
• ISSN: 0895-8378; 1091-7691
• DOI: 10.3109/08958378.2010.485226

We report on particle deposition in the tracheobronchial and pulmonary regions of the respiratory tract of the minipig and its dependence on particle size. Four animals breathing spontaneously via the nose were exposed for 1 h to known concentrations of three different polydisperse dry aerosols composed of bovine serum albumin (BSA) and an oxide of a rare earth element: Y2O3, Sm2O3, and Er2O3. The mass size distributions of the rare earth elements of the three test aerosols have mass median aerodynamic diameters of 0.9, 2.5, and, 4.3 µm, and geometric standard deviations of σg = 2.0, 1.8, and, 1.7. The extrathoracic, tracheobronchial, and pulmonary regions of the respiratory tract were dissected, separately lyophilized, and chemically digested by microwave-assisted high pressure digestion. The tracer element in each compartment was determined by inductively coupled plasma mass spectrometry. A mass balance equation relating the tracer mass found in the lung compartments to the tracer mass inhaled was solved by linear regression to obtain the deposition fraction as function of particle sizes for the tracheobronchial and the pulmonary lung region. Estimated values for the respiratory minute volume were used in this context. For coarse particles >6 µm, the deposition fraction is