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

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.