Filamentary rod‐shaped granules in clara cells of rats

摘要

AbstractThe 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 th