[Calcium-containing granules in frog bladder cells exposed to ionophore A-23187 and antidiuretic hormone]

Granules of granular cells of the frog bladder epithelium are shown concentrated near the apical cell membrane. The electron density of these granules is getting intensified after addition of antidiuretic hormone (ADH) and ionophore A23187. The intracellular localization of granules depends on the site of ionophore application--to the apical or basal membrane. The vacuolization of granular cells increases with the rising of water flow under the influence of ADH or ionophore A23187.