AJP - Lung Cellular and Molecular Physiology, Vol 267, Issue 1 64-L70, Copyright © 1994 by American Physiological Society
Morphometric analysis of pulmonary intracapillary leukocyte pools in ex vivo-perfused rabbit lungs
L. Ermert, H. R. Duncker, S. Rosseau, H. Schutte and W. Seeger
Institute of Anatomy and Cytobiology, Justus-Liebig-University of Giessen, Germany.
Characterization and quantification of lung intracapillary leukocytes is of
interest for a better understanding of immunological and inflammatory
features in this organ. We developed a technique of computer-assisted
measurement of digitalized electron-microscopic images and electronic data
processing for morphometry of intracapillary leukocyte pools in rabbit
lungs (L. Ermert, W. Seeger, and H.-R. Duncker, Cell Tissue Res. 271:
469-476, 1993). Measurements were undertaken in buffer-perfused isolated
lungs (avoiding any reentry of washed-out cells); perfusion fixation was
performed 7.5, 35, and 185 min after onset of artificial circulation (n = 5
each). Data were compared with that of nonperfused lungs fixed by tracheal
instillation (baseline). Total lung capillary neutrophil counts were 1.41 x
10(9), 1.35 x 10(9), 1.37 x 10(9), and 0.69 x 10(9) (baseline, 7.5, 35, and
185 min perfusion, respectively). Corresponding data for intracapillary
lymphocytes were 1.07 x 10(9), 0.84 x 10(9), 0.81 x 10(9), and 0.57 x
10(9); and for microvascular monocytes, data were 0.21 x 10(9), 0.19 x
10(9), 0.18 x 10(9), and 0.08 x 10(9). Ratios of cell volume and surface
variables of the different intracapillary leukocyte types did not change
during ex vivo lung perfusion. We conclude that the rabbit pulmonary
capillary bed harbors large pools of different leukocytes, which surpass
pool sizes of corresponding circulating cells and display very slow washout
kinetics under conditions of lung-buffer perfusion. A major impact of these
intracapillary leukocyte pools on immunological and inflammatory events in
isolated-perfused and transplanted lungs must be assumed.
