Korean J Nephrol.  2003 Jan;22(1):37-42.

Altered Regulation of Aquaporin-2 Water Channels in the Kidney Following Acute Blood Volume Depletion in Rats

• Li YS
• Oh Y
• Lee S
• Lee JU

Abstract

BACKGROUND
The present study was aimed to examine the regulation of aquaporin (AQP)-2 water channels in the kidney following blood volume depletion. METHODS: Male Sprague-Dawley rats were acutely blood volume-depleted by withdrawal of arterial blood up to 2% of body weight. The expression of AQP2 mRNA and protein was determined by reverse transcription - polymerase chain reaction and Western blot analysis, respectively, in the inner medulla of the kidney 1 and 3 hours after the hemorrhage. RESULTS: The mRNA expression of AQP2 was significantly increased 1 hour after the bleeding. However, neither the shuttling nor the total abundance of AQP2 proteins was significantly altered. On the contrary, 3 hours after the bleeding, the expression of AQP2 proteins as well as that of AQP2 mRNA was significantly increased. The shuttling of AQP2 proteins was also increased. CONCLUSION: These results suggest that an increased expression of AQP2 channels in the kidney may confer one of compensatory mechanisms restoring the circulating volume in an acute hypovolemic state.

Keyword

Aquaporin; Blood volume; Kidney

MeSH Terms

Animals
Aquaporin 2*
Aquaporins*
Blood Volume*
Blotting, Western
Body Weight
Hemorrhage
Humans
Hypovolemia
Kidney*
Male
Polymerase Chain Reaction
Rats*
Rats, Sprague-Dawley
Reverse Transcription
RNA, Messenger
Aquaporin 2
Aquaporins
RNA, Messenger