Micron-sized intrapulmonary particle deposition in the developing rat lung

作者：Schulz Holger^*; Eder Gunter; Bolle Ines; Tsuda Akira; Karrasch Stefan

来源：Journal of Applied Physiology, 2012, 112(5): 759-765.

DOI：10.1152/japplphysiol.01064.2011

• aerosol photometry
• deposition model
• rodent
• lung development

Schulz H, Eder G, Bolle I, Tsuda A, Karrasch S. Micron-sized intrapulmonary particle deposition in the developing rat lung. J Appl Physiol 112: 759-765, 2012. First published December 8, 2011; doi:10.1152/japplphysiol.01064.2011.-Little is known about the effects of postnatal developmental changes in lung architecture and breathing patterns on intrapulmonary particle deposition. We measured deposition in the developing Wistar-Kyoto rat, whose lung development largely parallels that of humans. Deposition of 2-mu m sebacate particles was determined in anesthetized, intubated, spontaneously breathing rats on postnatal days (P) 7 to 90 by aerosol photometry (Karrasch S, Eder G, Bolle I, Tsuda A, Schulz H. J Appl Physiol 107: 1293-1299, 2009). Respiratory parameters were determined by body plethysmography. Tidal volume increased substantially from P7 (0.19 ml) to P90 (2.1 ml) while respiratory rate declined from 182 to 107/min. Breath-specific deposition was lowest (9%) at P7 and P90 and markedly higher at P35 (almost 16%). Structural changes of the alveolar region include a ninefold increase in surface area (Bolle I, Eder G, Takenaka S, Ganguly K, Karrasch S, Zeller C, Neuner M, Kreyling WG, Tsuda A, Schulz H. J Appl Physiol 104: 1167-1176, 2008). Particle deposition per unit of time and surface area peaked at P35 and showed a minimum at P90. At an inhaled particle number concentration of 10(5)/cm(3), there was an estimated 450, 690, and 330 particles/(min x cm(2)) at P7, P35, and P90, respectively. Multiple regression models showed that deposition depends on the mean linear intercept as structural component and the breathing parameters, tidal volume, and respiratory rate (r(2) > 0.9). In conclusion, micron-sized particle deposition was dependent on the stage of postnatal lung development. A maximum was observed during late alveolarization (P35), which corresponds to human lungs of about eight years of age. Children at this age may therefore be more susceptible to micron-sized airborne environmental health hazards.

• 出版日期2012-3