Mnd. Peao et al., MORPHOLOGICAL EVIDENCE FOR MIGRATION OF PARTICLE-LADEN MACROPHAGES THROUGH THE INTERALVEOLAR PORES OF KOHN IN THE MURINE LUNG, Acta anatomica, 147(4), 1993, pp. 227-232
We have investigated the topography of particle-laden macrophages in t
he pulmonary tissue of CD-1 mice after intratracheal instillation of a
suspension of 250 mug of calcium tungstate. The mice were sacrificed
1, 3, 7 and 14 days after the particle deposition. 1-ung fragments wer
e,studied by scanning electron microscopy (SEM) coupled with X-rav mic
roanalysis that allowed in situ elemental identification of tungsten i
n the lungs. Tungsten-positive macrophages were distinctly located in
the lungs of mice sacrificed at 1-3 days when compared with samples fr
om 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 alve
olar ducts and sacs in the 7- to 14-day groups of mice. This suggests
that during pulmonary inflammation there is a redistribution of the pa
rticle-containing macrophages throughout the deep lung tissue. In high
-magnification SEM views, we observed that the tungsten-positive macro
phages presented numerous surface microvilli. Tungsten-laden phagocyte
s were detected in interalveolar fenestrae, at the so-called Kohn pore
s. This finding documents that the Kohn pores may be used by inflammat
ory cells as a pathway for the migration of phagocytes in between adja
cent alveolar sacs.