Ultrastructural localization of phospholipases in the Clara cell of the rat bronchiole

Am J Pathol. 1978 Dec;93(3):745-52.


The Clara cell of the bronchiole is unique to the lung; the cell's function is not clear. The localization of the lipid-hydrolase enzymes phospholipase, lysophospholipase, and lipase was examined ultrastructurally in the Clara cell of the rat bronchiole. The secretory granules of the Clara cell showed a strong reaction of lysophospholipase and a weak reaction of lipase. Phospholipase activity was not detected intracellularly. These findings suggest that the Clara cell secretes lipase-phospholipase into the bronchiolar lumen, thus catabolizing the pulmonary surfactant phospholipids.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Animals
  • Bronchi / enzymology*
  • Bronchi / ultrastructure
  • Cytoplasmic Granules / enzymology
  • Histocytochemistry
  • Lipase / metabolism*
  • Male
  • Phospholipases / metabolism*
  • Phospholipids / metabolism
  • Pulmonary Surfactants / metabolism
  • Rats


  • Phospholipids
  • Pulmonary Surfactants
  • Phospholipases
  • Lipase