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lamellar bodies

Monday 26 November 2007

Lamellar bodies are lysosomal-derived organelles of alveolar type II cells (type 2 pneumocytes).

Lamellar bodies appear in the cytoplasm of type 2 pneumocytes at about 20 weeks gestation. These lamellar bodies are secreted by exocytosis into the surface water layer lining the alveolar airspace, where the surfactant forms a meshwork of tubular myelin.

This alveolar surfactant can be both broken down by macrophages and/or reabsorbed into the lamellar structures of type II alveolar cells. Up to 90% of surfactant phosphatidylcholine is recycled from the alveolar space in the newborn.

The lipid transporter ABCA3 targets surfactant phospholipids to lamellar bodies.


- Edwards V, Cutz E, Viero S, Moore AM, Nogee L. Ultrastructure of lamellar bodies in congenital surfactant deficiency. Ultrastruct Pathol. 2005 Nov-Dec;29(6):503-9. PMID: 16316951