SEPARATION OF BRONCHOALVEOLAR CELLS FROM THE GUINEA-PIG ON CONTINUOUS DENSITY GRADIENTS OF PERCOLL - MORPHOLOGY AND CYTOCHEMICAL PROPERTIES OF FRACTIONATED LUNG MACROPHAGES

  • 1 January 1983
    • journal article
    • research article
    • Vol. 33  (2) , 119-126
Abstract
Cells recovered by lavage from lungs of normal guinea pigs were centrifuged on continuous density gradients of colloidal silica (Percoll). The gradient was divided into 6 fractions based on the banding pattern of cells. This pattern was highly reproducible from animal to animal. Cell types in the fractions were identified by morphological and cytochemical criteria and the volume of the cells was determined by measuring their diameter and tritiated H2O space. More than 70% of the cells put on the gradient were recovered in the 6 fractions, and there was no selective loss of cell types. Macrophages comprised > 95% of the cells in fractions 3, 4 and 5. These fractions were of intermediate density (1.037-1.078 g/ml) and together contained > 85% of the recovered macrophages. Fraction 6 (density 1.078-1.130 g/ml) was enriched for lymphocytes and granulocytes. Macrophages in fraction 5 were smaller, had more densely staining cytoplasm and exhibited more nonspecific cytoplasmic esterase activity than macrophages in other fractions (5 > 4 > 3 > 2). Density-gradient centrifugation on Percoll apparently is an efficient method for purifying guinea pig alveolar macrophages. Macrophages that differ in bouyant density also differ in morphologic and cytochemical properties. In a companion paper macrophages in fractions 3, 4 and 5 were reported to differ functionally as well.