Calcium distribution was measured in cultured utricular supporting cells following streptomycin sulfate (SM) intoxication. An organ culture system and potassium pyroantimonate (PA) precipitation method were used. Calcium ions were demonstrated in the otoconia and in the secretory granules of the supporting cells. When the supporting cells were exposed to SM lysosomes were increased and secretory granules were decreased in the cytoplasm. These lysosomes had many granules which contained calcium ion. It appeared that calcium secretion from the secretory granules was inhibited by SM and that this might lead to the reduction of otoconia.
