Abstract: Objective: To inspect whether ammonium chloride can specifically stimulate liver cell to change the internal RHCG and AQP8 gene expression .Methods： The human liver cell line (LO2)、thyroid cancer cell line(TPC-1)、ovarian cancer cell line(SKOV-3) and esophageal cancer cell line(9706) were cultured . MTT method was used to check the proliferation ability of those 4 cell lines after cells were treated with NH4Cl（work concentration:2.5、5、10、20、40、50 mmol/L, respectively）for 24h. QT-PCR and Western blotting were used to detect the RHCG and AQP8 gene expression of LO2 cells after treated with NH4Cl（5、10、20 mmol/L）for 6、12 and 24h. The RHCG and AQP8 gene expression of TPC-1、SKOV-3 and 9706 cells was detected after treated with NH4Cl（10 mmol/L）the same method above. Results: MTT method finds the growth inhibitory rate in LO2 cells increase with ammonia concentration increasing, which is significantly greater than that in other 3 cell lines. RT-PCR finds that RHCG mRNA in LO2 cells decreased when treated with 10 mmol/L ammonium chloride for 6 hours (p<0.05). while AQP8 mRNA in LO2 cells increased when treated with 10mmol/l ammonium chloride for 12 hours (p<0.05);10 mmol/L. Western blot finds that the AQP8 protein in LO2 cells increased when treated with 10mmol/L ammonium chloride for 24 hours (p<0.05), while the RHCG protein expression has no change. No obvious change is found in the AQP8 and RHCG expression in other cells when treated with ammonia of the same concentration within the same time. Conclusion: In the environment with ammonia of high concentration, human liver cells can maintain the balance of absorbing ammonia by changing RHCG and AQP8 expression to reduce the harm of ammonia to liver cells, while other cells have no such function.

Key words: Gammonium chloride, ammonium transporter , RHCG , AQP8