Fig. 2. Typical examples of effects of amiloride (Am; 10^–4 mol l^–1), acetylcholine (ACh; 10^–3 mol l^–1) and ATP (10^–3 mol l^–1) on short-circuit current (SCC) of tadpole skin cultured for 11–13 days with corticoids supplemented with growth hormone (GH; 1 µg ml^–1) or prolactin (PRL; 1 µg ml^–1), with intact tadpole skin included as control.