Decreased abundance of urinary exosomal aquaporin-1 in renal ischemia-reperfusion injury.

Urinary exosomes, secreted into urine from renal epithelial cells, are known to contain many types of renal functional membrane proteins. Here, we studied whether renal ischemia-reperfusion (I/R) affects urinary exosomal aquaporin-1 (AQP1) excretion in rats subjected to renal I/R and patients who underwent renal transplantation. Immunoblotting studies demonstrated reduction of the urinary exosomal AQP1 level even at 6 h after renal I/R, and the level continued to be low over 96 h after I/R.