Peritoneal function: the role of aquaporins.
The aquaporins (AQPs) constitute a large family of water channels that play a part in transcellular water movement in many tissues. They are particularly abundant and important in the kidney and the lung. Derangement of AQP structure or function leads to a variety of water-balance disorders. Aquaporin-1 (AQP1) is constitutively expressed in the endothelial cells of the capillaries and venules that provide the ultrasmall pores predicted by the three-pore model of water movement during peritoneal dialysis. The ultrasmall pores are critical for ultrafiltration. In addition, AQP1 and AQP3 are constitutively expressed in peritoneal mesothelial cells. The expression of those AQPs is upregulated by hyperosmolality. Reduced expression or function of AQP1 may be responsible for some cases of ultrafiltration failure, but further evidence is required to establish that link.
Lai
Kar Neng
KN
Department of Medicine, University of Hong Kong, Queen Mary Hospital, Hong Kong SAR, China. knlai@hkucc.hku.hk
Lam
Man Fai
MF
Leung
Joseph C
JC
D000818:Animals; D020346:Aquaporins / Q000502:physiology*; D006801:Humans; D010537:Peritoneum / Q000502:physiology*
D020346:Aquaporins