Filamentary rod-shaped granules in clara cells of rats

Authors

  • Dr. J. Baert,

    Corresponding author
    1. Interdisciplinary Research Centre, Laboratory of Electron Microscopy, Katholieke Universiteit Leuven, Campus Kortrijk, B-8500 Kortrijk, Belgium
    • K.U.L.A.K., afd. Histologie, Universitaire Campus, B-8500 Kortrijk, Belgium
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  • M. P. Vandenberghe

    1. Interdisciplinary Research Centre, Laboratory of Electron Microscopy, Katholieke Universiteit Leuven, Campus Kortrijk, B-8500 Kortrijk, Belgium
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Abstract

The bronchiolar Clara cells of rats contain characteristic rodshaped granules always surrounded by a unit membrane. These granules contain thin filaments about 9 to 10 nm in diameter lying in a pale matrix. Our morphological results suggest that the filamentary rod-shaped granules originate from the common, round-to-oval, electron-dense Clara cell granules, as we found different intermediate structures between these two kinds of granules. The electron-dense granules are digested by pepsin, whereas the filamentary rod-shaped granules are apparently not affected. The biochemical nature and the possible function of the filamentary rod-shaped granules are also discussed in relation to the secretory activity of the Clara cells.

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