The molecular physiology of the urinary concentrating mechanism:
regulation of aquaporin water channels by vasopressin.
Knepper, Mark A.
Renal Mechanisms Section, Laboratory of Kidney and Electrolyte
Metabolism, National Heart, Lung and Blood Institute, National
Institutes of Health, Bethesda, MD 20892-1598
APStracts 3:0186F, 1996.
The purpose of this review is to illustrate the application of
molecular methodologies to the investigation of a fundamentally
integrative problem in renal physiology, viz. the mechanism of
regulation of water excretion by the kidney and the concomitant
concentration of solutes in the urine. A new revolution in renal
physiology is occurring as new research tools have become available
as a result of the cloning of complementary DNAs for many of the
major transporters and receptors in the renal medulla. Among the
important renal medullary transporters are the aquaporin water
channels which mediate the osmotic water transport across renal
medullary epithelia. One of these water channels, aquaporin-2, has
been shown to be the target for short-term regulation of collecting
duct water permeability by vasopressin. In addition, two collecting
duct water channels, aquaporin-2 and aquaporin-3, are targets for
long-term regulation by vasopressin through effects on the absolute
expression levels of the water channel proteins. This review focuses
on the mechanisms of both short- and long-term regulation of these
water channels by vasopressin.
Received 10 October 1996; accepted in final form 15 October 1996.
APS Manuscript Number F288-6.
Article publication pending Am. J. Physiol. (Renal Fluid Electrolyte
Physiology).
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 5 November 1996