Figure 3. Effect of rat amylin (10⁻⁷m) on ²²Na extrusion from soleus muscle.

Muscles were loaded for 60 min at 30 °C in buffer containing ²²Na (10 μCi ml⁻¹), and then washed for 8 × 10 min at 30 °C in eight tubes containing unlabelled buffer without or with the indicated additions. Ouabain (10⁻³m), when added, was present from the onset of washout. Horizontal bar indicates the addition of rat amylin. By successive addition of the ²²Na activity in the washout tubes to that in the muscle at the end of experiment, activity in the muscle before each transfer was calculated. On the basis of these values, the fractional loss of ²²Na activity could be calculated for each 10 min washout period. Each point represents the mean of observations on six muscles with bars denoting s.e.m.* Significant difference from control muscles (P < 0.01).