Cyclic AMP is sufficient for triggering the exocytic recruitment of aquaporin-2 in renal epithelial cells.

ABSTRACT: The initial response of renal epithelial cells to the antidiuretic hormone arginine vasopressin (AVP) is an increase in cyclic AMP. By applying immunofluorescence, cell membrane capacitance and transepithelial water flux measurements we show that cAMP alone is sufficient to elicit the antidiuretic cellular response in primary cultured epithelial cells from renal inner medulla, namely the transport of aquaporin-2 (AQP2)-bearing vesicles to, and their subsequent fusion with, the plasma membrane (AQP2 shuttle). The AQP2 shuttle is evoked neither by AVP-independent Ca(2+) increases nor by AVP-induced Ca(2+) increases. However, clamping cytosolic Ca(2+) concentrations below resting levels at 25 nM inhibited exocytosis. Exocytosis was confined to a slow monophasic response, and readily releasabl

SUBMITTER: Lorenz D 

PROVIDER: S-EPMC1315811 | biostudies-literature | 2003 Jan

REPOSITORIES: biostudies-literature