Modification of mitochondria-rich cells in different ionic conditions: changes in cell morphology and cell number in the skin of Xenopus laevis.

Xenopus laevis were kept in salt water (1.25% NaCl), distilled water, or tapwater for a month. Compared to the animals kept in tap water, the number of mitochondria-rich (MR) cells in the NaCl-adapted animals was significantly reduced, while it was increased in those maintained in distilled water. In addition, the MR-cells of NaCl-adapted animals lost their slender flask shape and developed large deposits of glycogen. The alteration of this cell type in conditions of high or low salinity may reflect a role of MR-cells in adaptation to different ionic environments.