Stretch induces granule exocytosis in toad urinary bladder.

Evidence from this sections and freeze-fracture is presented showing that stretch induces a burst of exocytosis in granular cells of the toad urinary bladder epithelium. Since the role of granule exocytosis in hormonally-induced permeability changes in this tissue has not yet been clarified, we propose that the stretch factor is an important parameter to consider and standardise in future physiological and morpho-functional studies using this model transporting system.