Fig. 1. A typical example of the effect of prolactin (PRL) on short-circuit current (SCC) I tree frog skin (inset shows data for the initial phase of response). Values are means ± S.E.M.; N = number of experiments. PRL (10 µg ml^-1) was applied to the basolateral side of the skin and amiloride (Am; 10^-4 mol l^-1) to the apical side, at the times shown.