SEM Studies of Comparative Membrane Remodeling by Endocytosis in Toad UrinaryBladders Following Withdrawal of ADH and MZ

摘要

Vasopressin (ADH) and mezerein (MZ) induce transmembrane water flow through waterchannels inserted into the apical plasma membrane. The water channels are then recycled into the cytosol during retrieval following withdrawal of vasopressin or mezerein. Previously, we demonstrated that membrane retrieval occurs within 5 min following withdrawal of ADH or MZ even after stimulation for 15 or 10 min respectively. The apical membranes appear to undergo remodeling prior to a complete membrane restoration. The loss in microstructure are restricted to the mucosal face of the apical membrane. However, little is known about the apical membrane recycling process during prolonged periods of hormone stimulation. We currently report on surface membrane remodelling in toad urinary bladders following prolonged stimulation with ADH and subsequent retrieval following removal of hormone.