Morphology of globule leucocyte from bovine bronchopulmonary lavage

It has hitherto been assumed that the globule leucocytes (GL) occur as free cells in the airways of animals. The present study provides definite evidence for the occurrence of these cells in the bronchopulmonary lavage of cattle. At the light-microscopic level, the GL was a round to elongate cell containing the characteristic large, round, metachromatic granules and an eccentric nucleus with a prominent nucleolus. Ultrastructurally, the cell was round, approximately 15 micron in diameter, and contained round, electron-dense granules which measured approximately 1.25 micron in diameter. The cell nucleus was endowed with abundant heterochromatin. The cytoplasm had only inconspicuous organelles. We conclude that the bovine GL is a specific cell which reaches the airway lumen following migration from the lining of the bronchopulmonary mucous membrane.