Intracellular calcium localization in stimulated, non-stimulated and repressed eccrine sweat glands.

Acinar cells of eccrine sweat glands from control, pilocarpine-treated, and atropine-treated rats were studied using a potassium pyroantimonate technique for calcium localization at the ultrastructural level. This was done in order to identify intracellular compartmentalization of calcium and to elucidate any calcium translocation that might occur during the secretion process. Calcium-pyroantimonate complexes were identified in the mitochondria, plasma membrane and cytoplasmic vesicles of the untreated and the atropine-treated specimens. These complexes decreased drastically in the actively secreting cells. The function of calcium in sweat gland secretion and the action of the utilized pharmacological agents on membrane calcium are discussed.