Korean J Nephrol.  2002 Jul;21(4):525-530.

Role of Nitric Oxide in the Regulation of Aquaporin-2 Water Channels in Rat Kidney

• Kim YJ
• Yoo GJ
• Lee JU

Abstract

BACKGROUND: The present study was aimed at investigating whether there is a mechanism exerted by endogenous nitric oxide(NO) in the regulation of aquaporin(AQP) water channels in the kidney.
METHODS
Male Sprague-Dawley rats were treated with N(G)-nitro-L-arginine methyl ester(L-NAME, 40 mg/L drinking water) to inhibit the endogenous generation of nitric oxide. Four weeks later, total abundance and shuttling of AQP2 proteins were determined in different regions of the kidney.
RESULTS
Chronic inhibition of NO synthesis increased the expression of AQP2 channels in cortex, outer medulla, and inner medulla of the kidney. The AQP2 shuttling was not significantly altered, as evidenced by an unaltered ratio of AQP2 expression in the membrane fraction versus that in the cytoplasmic fraction.
CONCLUSION
It is suggested that endogenous NO activity plays a tonic inhibitory role in the expression of AQP2 channels in the kidney.

Keyword

Nitric oxide; Aquaporin-2 water channels

MeSH Terms

Animals
Aquaporin 2*
Aquaporins*
Cytoplasm
Drinking
Humans
Kidney*
Male
Membranes
Nitric Oxide*
Rats*
Rats, Sprague-Dawley
Aquaporin 2
Aquaporins
Nitric Oxide