Comparison of the metabolism of alveolar macrophages from humans, rats, and rabbits: phorbol myristate acetate.

Metabolic activities of unstimulated or stimulated AMs from humans, rats, and rabbits were examined and compared in vitro. Rates of oxygen consumption, chemiluminescence, and glucose (1- or 6-14C) oxidation by unstimulated AMs from these three species increased following stimulation of the AMs by bacteria or PMA. Although the absolute metabolic responses of AMs from humans, rats, or wild rabbits were different, the metabolic activities from each species were nearly identical when compared on the basis of protein content of the cells. In contrast to the enhanced biochemical responses of AMs from humans, rats, or wild rabbits, stimulated AMs from certain commercially supplied rabbits failed to increase their metabolism. The failure of AMs from these rabbits to respond metabolically was probably due to an acquired abnormality resulting from their care and storage at the supplier. The defect was associated with the presence of large numbers of Bordetella bronchiseptica organisms in the lavage effluents from these commercially supplied rabbits. This abnormality in metabolism of AMs was reversed following prolonged residence of the rabbits in the laboratory, and the correction of the defect was accompanied by a disappearance of B. bronchiseptica from the lavage fluid. The results comprehensively compare and contrast the metabolism of AMs from humans and animals and emphasize the need to document the appropriateness of animal models before using them to predict biologic reactions of humans.