Fig. 1. Effect of growth hormone (GH) on development of short-circuit current (SCC) across cultured tadpole skin (A) and effect of amiloride (Am) on the SCC (B). Skin of tadpoles at stages XII–XV was cultured for 11–13 days with corticoids supplemented with various concentrations of GH. Amiloride (10^–4 mol l^–1) was applied to the apical side of the skin. SCC was measured as the difference between the peak response and the baseline SCC, as indicated in B. Values are means ± S.E.M. (no. of experiments is indicated in parentheses).