Localization of calcium in fibrocytes associated with the "substantia amorpha" in the skin of toad, Bufo bufo (L.) (Amphibia, Anura).

Using the potassium pyroantimonate-technique in the fibrocytes associated with the calcium-containing granules of the substantia amorpha within the dermis of Bufo bufo numerous electron-dense deposits have been observed. Reaction product lies in the mitochondria, at the plasma membranes and in various vesicular structures. X-ray microanalysis confirmed that pyroantimonate was predominantly associated with calcium. It is suggested that certain organelles of the fibrocytes are capable of sequestering calcium ions and that the fibrocytes are involved in the Ca-metabolism of the substantia amorpha.