SEM Studies on the In Vivo Uptake of Aspergillus Terreus Spores by Alveolar Macrophages.
Green-FH; Olenchock-SA; Willard-PA; Major-PC
Scanning Electron Microscopy, SEM, Inc., AMF O'Hare; Chicago, Illinois 1980:307-314
The uptake of Aspergillus-terreus (Aspergillus) spores by alveolar macrophages was studied in-vivo. Male New-Zealand-white-rabbits were intratracheally instilled with 7 x 10(6) Aspergillus spores in a volume of 1.0 milliliter (ml). CRL/BR-rats were instilled intratracheally with 5 x 10(7) Aspergillus spores in 0.25ml. The animals were killed at selected times up to 2 hours (rabbits) or 48 hours (rats) after treatment, and the lungs were removed and sectioned. The sections were examined by light and electron microscopy supplemented by heavy metal staining and back scattered electron imaging. Sera from all animals were examined for precipitating antibodies by counterimmunoelectrophoresis against commercially available Aspergillus extract. All animals were negative for demonstrable precipitating antibodies. Uptake of Aspergillus spores by macrophages on the surface of the alveoli and airways was extremely rapid. More than 95 percent of the spores were associated with macrophages 3 hours after treatment. The number of spores within a macrophage ranged from one to 20. No spores (either free or within macrophages) were seen penetrating the bronchial or alveolar epithelium at any time after exposure. Very few polymorphonuclear leukocytes were seen. Macrophages with intracytoplasmic spores were seen on the bronchial mucosa at all times up to 48 hours. Between 3 and 48 hours, the number of macrophages containing spores decreased rapidly in the peripheral alveoli, whereas the number of macrophages arising from the respiratory bronchioles increased. The authors conclude that in- vivo phagocytosis of spores is an extremely rapid event in rats and rabbits and only minimal transport of spores through the alveolar wall seems to occur.
Lung-cells; Alveolar-cells; Absorption-rates; Fungi; Lung-tissue; In-vivo-studies; Laboratory-animals; Microorganisms; Microscopic-analysis; Phagocytes;
Scanning Electron Microscopy, SEM, Inc., AMF O'Hare; Chicago, Illinois