Details

Autor(en) / Beteiligte

• Fritsch, Paul
• Masse, Roland

Titel

Overview of Pulmonary Alveolar Macrophage Renewal in Normal Rats and during Different Pathological Processes

Ist Teil von

• Environmental health perspectives, 1992-07, Vol.97, p.59-67

Ort / Verlag

United States: National Institute of Environmental Health Sciences. National Institutes of Health. Department of Health, Education and Welfare

Erscheinungsjahr

1992

Link zum Volltext

Quelle

Elektronische Zeitschriftenbibliothek (Open access)

Beschreibungen/Notizen

• We report experimental results on pulmonary alveolar macrophage (PAM) renewal in healthy rats and in rats treated with particles introduced in the lungs. Morphometric studies showed that the lungs of normal rats of the strain used in our study contain 20× 106PAM, 50× 106monocytes in alveolar capillaries, and about 3× 105interstitial macrophages. Pulse labeling with a tritiated thymidine (3HT) gave a labeling index of 0.4% for the monocytes, of which a few could be observed in mitosis within alveolar capillaries. These monocytes are likely to be the PAM precursors. The daily input (> 4%) by PAM proliferation exceeds PAM loss by migration to the upper respiratory tract (2.5%). The life span of PAM was measured by sequential counting of lavaged cells after labeling with [125I]iododeoxyuridine instilled intratracheally. The pulmonary lavage procedure used allowed us to recover at least 80% of the whole PAM population. A daily loss of PAM of 8-9% was measured, of which loss by death in the endoalveolar compartment was estimated at 5-6%. During the pathological processes studied, several parameters of PAM renewal were shown to be modified. PAM migration to the upper respiratory tract was frequently inhibited, PAM cytotoxicity was observed, and PAM proliferation increased in some cases and decreased in others. Under most of the pathological conditions investigated, the renewal of endoalveolar macrophages appeared quite different from that in normal rats, and direct blood monocyte migration to the endoalveolar compartment became a major component of PAM renewal.