RESUMO
AIM: To clarify the role of Cl - in regulatory volume decrease (RVD) of nasopharyngeal carcinoma cells (CNE-2Z).METHODS: Analysis of living cell images was used to detect the volume changes following exposure to hypotonic solution. Iron replacement and block of iron channels were also applied in the present study. RESULTS: Extracelluar hypotonic treatment made the cells swell and induced RVD. The RVD was correlated positively to the swelling in the range of 160-230 mOsmol/L. Substitution of gluconate for Cl - in perfusing solutions markedly increased RVD. Depletion of cellular Cl - abolished, and chloride channel blockers inhibited RVD. CONCLUSION: Cl - is the key iron to establish the RVD in CNE-2Z cells. Activation of Cl - channels and Cl - efflux are the major mechanisms of RVD.