Figure 2.
Dynorphin peptides modulate ASIC1a steady-state desensitization in a concentration-dependent manner. A, Representative trace showing concentration dependence for big dynorphin modulation of ASIC1a expressed in oocytes. Peptides were applied at the indicated concentrations and steady-state desensitization was induced by pH 7.0 conditioning as before. ASIC1a current was evoked by application of pH 5.0. B, Quantification of peptide concentration effects on ASIC1a for dynorphin A and big dynorphin. Peak current amplitude was normalized to maximal current amplitude (I/I max) in the absence of peptide. The data were fitted to a Hill equation with an EC50 of 32.8 ± 11.5 μm (n = 8) for dynorphin A and an EC50 of 26.4 ± 14.8 nm (n = 6) for big dynorphin (p < 0.001 for peptide EC50; unpaired t test). Error bars are the SEM. Dyn., Dynorphin.