Abstract: Studies have confirmed that the water channel aquaporin-1 (AQP1) is expressed on peritoneum. AQP1 is considered to be the molecular counterpart of the ultrasmall pore on peritoneum, and plays a fundamental role in transcellular water transport across the peritoneum. The changes of its structure, function or distribution in cells may lead to ultrafiltration failure（UFF）, being one of the main causes for peritoneal dialysis (PD) failure. A common promoter variant in the gene coding AQP1 is associated with the decreased  ultrafiltration（UF）, patient prognosis and technology survival, indicating that genetic factors affect the efficiency of peritoneal ultrafiltration. Factors regulating AQP1 expression include permeability regulation, pharmacological regulation, pH regulation, AQP1 channel activity regulation, and others. Recent studies have found that peritoneal mesothelial cells (PMCs) also express AQP1 and are related to peritoneal ultrafiltration. AQP1 may have other functions such as protecting PMCs and the peritoneum from fibrosis. AQP1 as a regulatory target for the amelioration of ultrafiltration has been recently emphasized, especially regulating AQP1 expression at the gene level and using APQ1-selective medicines. In this review, the research progress in the relationship between AQP1 and peritoneal ultrafiltration in PD is introduced.

Key words: Aquaporin-1, Peritoneal dialysis, Ultrafiltration