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. 2003 Jun 18;551(Pt 1):79–92. doi: 10.1113/jphysiol.2003.046482

Figure 5. Inhibition of SCC responses to 7,8-benzoquinoline by DNDS.

Figure 5

The SCC produced in response to 7,8-benzoquinoline (250 μM, bs) in a Calu-3 monolayer was inhibited by subsequent addition of the di-sodium salt of 4,4′-dinitrostilbene-2,2′-disulphonic acid (DNDS) plus acetazolamide given together. DNDS and acetazolamide were used at concentrations of 3 mM (bl) and 100 μM (bs), respectively. Finally bumetanide (20 μM, bl) was added. After the experiment shown in A the tissue was washed and a further experiment carried out as in B. Here DNDS and acetazolamide were added first, followed by 7,8-benzoquinoline. Note that the response is severely curtailed but reaches a maximal value of 88 μA, not different from the steady-state value after DNDS and acetazolamide in A (89 μA). The shaded area in A represents the current removed by DNDS plus acetazolamide and is equivalent to 0.43 μequiv. C, the effects of sequential addition of acetazolamide (100 μM, bs) and DNDS (3 mM, bl) on the response to 7,8-benzoquinoline (250 μM, bs) are shown. D gives the composite data from 6 experiments.