Figure 4.

Positional effect of substituent group on the phenyl ring of blocker that affects block of Ca²⁺-activated Cl^- current. (A) Comparison of chemical structure, IC₅₀ and dose response between N-(2-nitrophenyl)anthranilic acid, N-(3-nitrophenyl)anthranilic acid and N-(4-nitrophenyl)anthranilic acid in which the nitro (-NO₂) group on the benzene ring is positioned at ortho, meta and para position. (B) Comparison of chemical structure, IC₅₀ and dose response between flufenamic acid and derivatives N-(2-trifluoromethylphenyl)anthranilic acid and N-(4-trifluoromethylphenyl)anthranilic acid in which the trifluoromethyl (-CF₃) group on the benzene ring is positioned at ortho, meta and para position. Shaded boxes indicate the substituent groups tested. n indicates number of oocytes. Error bars indicate SEMs.