Morphological evidence for migration of particle-laden macrophages through the interalveolar pores of Kohn in the murine lung.
We have investigated the topography of particle-laden macrophages in the pulmonary tissue of CD-1 mice after intratracheal instillation of a suspension of 250 micrograms of calcium tungstate. The mice were sacrificed 1, 3, 7 and 14 days after the particle deposition. Lung fragments were studied by scanning electron microscopy (SEM) coupled with X-ray microanalysis that allowed in situ elemental identification of tungsten in the lungs. Tungsten-positive macrophages were distinctly located in the lungs of mice sacrificed at 1-3 days when compared with samples from mice killed 7-14 days after the calcium tungstate instillation. At 1-3 days, the tungsten-carrying macrophages were accumulated near the terminal bronchioles whereas they were seen predominantly in the alveolar ducts and sacs in the 7- to 14-day groups of mice. This suggests that during pulmonary inflammation there is a redistribution of the particle-containing macrophages throughout the deep lung tissue. In high-magnification SEM views, we observed that the tungsten-positive macrophages presented numerous surface microvilli. Tungsten-laden phagocytes were detected in interalveolar fenestrae, at the so-called Kohn pores. This finding documents that the Kohn pores may be used by inflammatory cells as a pathway for the migration of phagocytes in between adjacent alveolar sacs.
Peão
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MN
Department of Anatomy, Abel Salazar Institute for the Biomedical Sciences, Porto, Portugal.
Aguas
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AP
de Sá
C M
CM
Grande
N R
NR
D000280:Administration, Inhalation; D000818:Animals; D001980:Bronchi / Q000166:cytology / Q000648:ultrastructure; D017610:Calcium Compounds / Q000008:administration & dosage; D002465:Cell Movement; D005260:Female; D016676:Macrophages, Alveolar / Q000502:physiology / Q000648:ultrastructure*; D051379:Mice; D008855:Microscopy, Electron, Scanning; D011650:Pulmonary Alveoli / Q000166:cytology / Q000648:ultrastructure*; D017973:Tungsten Compounds / Q000008:administration & dosage
D017610:Calcium Compounds; D017973:Tungsten Compounds; C018858:calcium tungstate