Vasopressin Receptor Signaling and Cycling of Water Channels in Renal Epithelia (HBC)
Abstract
The role of renal cortical epithelia in fluid reabsorption and regulation of urinary volume is crucial in maintaining homeostasis with the hormone vasopressin (ADH) playing a critical role. We have been studying the mechanisms of transmembrane water flow by exocytosis and retrieval of water channels by endocytosis as induced by vasopressin. Water flow processes are also induced by mezerein (MZ), an activator of protein kinase C (PKC), in a manner very similar to what were produced by ADH. Scanning and transmission electron microscopy demonstrated that the membrane recovery process was associated with an induction of invaginations only at the apical plasma membranes involving many granular epithelial cells. During endocytosis, apical membranes underwent transition with a loss of both microridges and microvilli prior to membrane restoration to the unstimulated state. Time-course studies indicated that increases in cell-surface endocytosis were correlated with a decrease in water loss from the urinary bladder sacs.
Document Details
- Document Type
- Technical Report
- Publication Date
- Aug 27, 1993
- Accession Number
- ADA271909
Entities
People
- Abdul J. Mia
- Thomas Yorio