Abstract: Objective To investigate whether the expression of aquaporin-1(AQP-1) on the pleura is related with tuberculous pleural effusion in a rat model.  Methods Forty-eight Wistar rats were randomly and equally divided into tuberculous pleural effusion (days 1, 3, and 5) and control groups.The rats in tuberculous pleural effusion groups were injected into pleural cavities with 2 ml(9×10⁶ CFU) of Mycobacterium tuberculosis strain H37Rv,and the rats in control group were injected with 2 ml of saline. The visceral and parietal pleural tissues were taken and processed for detecting the level of AQP-1 by real-time PCR (RT-PCR), Western blot, and immunohistochemistry.  Results The rats in tuberculous pleural effusion group(days 5) showed bilateral pleural effusions. The peak amount of pleural fluid occurred on day 3 (4.4±1.2 ml). The level of AQP-1 mRNA and protein were significantly increased in both the parietal and visceral pleura from the rats in the tuberculous pleural effusion groups as compared with the control group (P<0.05).  Conclusion s The expression of AQP-1 was increased on the pleura of rats with tuberculosis. These Results suggest AQP-1 is likely involved in the formation of tuberculous pleural effusions.

Key words: tuberculosis, pleural, pleural effusion, aquaporin-1