The ultrastructural study of glycogen and lamellar bodies in the development of fetal monkey lung.

Developing fetal monkey lung tissues were studied at the gestational period of 135-145 days. In general, glycogen is distributed throughout the cytoplasm of the type II pneumocytes at this gestational period. It is of interest that we found a structural relationship between glycogen particles and lamellar body formation in the type II pneumocytes. The glycogen particles were found inside the electron-dense pre-granules and the immature lamellar bodies. Some of the fully matured lamellar bodies also contained glycogen. This phenomenon has not been observed previously, and it supports the evidence that there is a close and direct structural relationship between glycogen and the development of lamellar bodies at this stage of lung development in the type II pneumocytes.