[Structural characteristics and innervation of chromaffin tissue in the adrenal gland of the axolotl].

Each adrenal gland of the Axolotl consists of a strip lying all along the medio-lateral edge on the ventral surface of the kidney. The gland is composed of interrenal cells (IC) and chromaffin cells (CC). The IC contained a great number of pleomorphic lipid droplets, smooth endoplasmic reticulum and elongated mitochondria with tubulo-vesicular cristae. Two types of CC, always disposed in clusters and exhibiting long cytoplasmic processes were described according to the electron density, size and shape of granules distributed in their cytoplasm; noradrenaline cells (NA) and adrenaline cells (A). The innervation and ultrastructural differences from the adrenal gland of other Anurans were discussed.