Long-term regulation of aquaporins in the kidney.
Marples, David, J_rgen, Fr_kiaer & S_ren Nielsen.
Department of Physiology, University of Leeds, Leeds LS2 9NQ,
England; _Institute of Experimental Clinical Research, and
_Department of Cell Biology, Institute of Anatomy, University of
Aarhus, DK-8000 Aarhus, Denmark.
APStracts 5:0216F, 1998.
The discovery of the aquaporin family of water channels has greatly
improved our understanding of how water crosses epithelial cells,
particularly in the kidney. The study of the mechanisms involved in
the regulation of collecting duct water permeability, in particular,
has advanced very rapidly since the identification and
characterisation of aquaporin 2 in 1993. One of the more surprising
findings has been the dramatic long-term changes that are seen in the
abundance of this protein, and the recognition that these changes
represent a way of modulating the acute antidiuretic effects of
vasopressin. Furthermore, such changes seem to be of aetiological and
pathological significance in a number of clinical disorders of water
balance. This review focusses on the various conditions in which
aquaporin-2 expression is altered (either increased or decreased),
and on what this can tell us about the signals and mechanisms
controlling these changes. Ultimately, this may be of great value in
the clinical management of water balance disorders. Evidence is also
now beginning to emerge that there are similar changes in the
expression of other renal aquaporins, which had previously been
thought to provide an essentially constitutive water permeability
pathway, suggesting that they too should be considered as regulatory
factors in the control of body water balance.
Received 17 December 1998; accepted in final form 17 December
1998.
APS Manuscript Number F329-8.
Article publication pending Am. J. Physiol. (Renal Physiology).
ISSN 1080-4757 Copyright 1998 The American Physiological Society.
Published in APStracts on 18 December 1998