Korean J Nephrol.  2006 Nov;25(6):887-892.

Effects of Nitric Oxide Synthesis Inhibition on Indomethacin-Induced Downregulation of Renal Aquaporins in Rats

• Bae EH
• Park CH
• Kim SW
• Ma SK
• Kim NH
• Choi KC
• Lee JU

Abstract

BACKGROUND
The present study aimed to determine whether there is a regulatory mechanism exerted by endogenous nitric oxide (NO) in the regulation of aquaporin (AQP) water channels in the kidney.
METHODS
Male Sprague-Dawley rats were used. They were divided into 4 groups: 1) L-NAME group was treated with N(G)-nitro-L-arginine methyl ester (L-NAME, 100 mg/L drinking water) for 1 week, 2) indomethacin group was treated with indomethacin (5 mg/kg, twice a day, i.p.) for 2 days, 3) L-NAME/ indomethacin group was treated with L-NAME for 1 week in which indomethacin was cotreated for the last two days, and 4) control group was kept untreated. The abundance of AQP2 and AQP3 proteins was determined in the inner medulla of the kidney.
RESULTS
The expression of AQP2 and AQP3 proteins was significantly decreased by indomethacin. L-NAME abolished the indomethacin-induced decreases of AQP channels, although it did not significantly affect the expression of AQP channels by itself.
CONCLUSION
These results suggest that endogenous NO system, when stimulated, may downregulate the expression of AQP2 and AQP3 channels in the kidney.

Keyword

AQP channels; Indomethacin; N(G)-nitro-L-arginine methyl ester

MeSH Terms

Animals
Aquaporin 3
Aquaporins*
Down-Regulation*
Drinking
Indomethacin
Kidney
NG-Nitroarginine Methyl Ester
Nitric Oxide*
Rats*
Rats, Sprague-Dawley
Aquaporin 3
Aquaporins
Indomethacin
NG-Nitroarginine Methyl Ester
Nitric Oxide