Objective: To observe the influence of Chinese herb Astragalus on peritoneal structure and function during the peritoneal dialysis especially on tight junction(TJ). Method: Ninty-six chronic nenal failure (CRF) SD rats were divided into 4 groups: control group (NS)

model group(4.25% peritonal dialysis solution(PDS) and LPS)

low Astragalus group (1 g ·kg-1

ip) and high Astragalus group(2 g ·kg-1

ip). A 2-hour peritoneal equilibration test was performed after 4 weeks. Peritonal clerance ratio

total protein

and net ultrafiltration volume were determined. Peritoneal membrane histology was evaluated by light microscopy and transmission electron microscopy. Immuno-histochemical staining and reverse transcript-polymerase chain reaction (RT-PCR) techniques were used to investigate zonula occluden-1(ZO-1) and laminin (LN) expression. Result: Ultrafiltration volume and BUN clearance rate were remarkably reduced in model group (P<0.05)

and the expression of HA concentration was increased (P<0.05). In model group

peritoneal membrane histology showed mesothelial cells detached from peritoneal membrance and matrix accumulation by light microscopy

and distruction of TJ was also showed by transmission electron microscopy. While Astragalus groups showed less injury in the peritoneal mesothelial cell. Immuno-histochemical staining showed the expression of ZO-1 was lower and the LN was higher in model group

as well as Astragalus group. And the RT-PCR showed the same levels. Conclusion: The treatment of Astragalus can improve the function of peritoneal dialysis by protection of peritoneal tissues including peritoneal mesothelial cell and tight junction. However

it doesn’t play a significant role in the expression of ZO-1.