Figure 1
From: Insulin enhances acid-sensing ion channel currents in rat primary sensory neurons
Enhancement of ASIC currents by insulin in rat DRG neurons. (A) In the presence of 5 μM AMG9810, capsaicin (Cap, 100 nM) induced no membrane currents. However, a 5 s exposure of pH 6.0 acidic solution produced a rapid inward current (IpH6.0) in the same DRG neuron. The IpH6.0 was blocked by amiloride (Amil, 100 μM) and APETx2 (2 μM). (B) The IpH6.0 was enhanced by insulin pretreatment (300 nM for 5 min) and recovered after the washout of insulin. In contrast, the IpH6.0 was not affected by heat-inactivated insulin (300 nM). Insulin (300 nM) or heat-inactivated insulin (300 nM) was pre-applied to a recorded DRG cell for 5 min. (C) The bar graph shows that the amplitude of the IpH6.0 under different conditions. **p < 0.01, n.s., not significant, compared with the control. The data were analyzed by one-way ANOVA followed by Tukey’s post hoc test. n = 10 cells from 6 rats. (D) The enhancing effect of insulin (300 nM) on the IpH6.0 increased with increasing duration of insulin preapplication from 0 to 5 min. Each point represents the mean ± S.E.M. of 7–10 cells from 5–6 rats. (E) The graph shows the concentration-effect curve of insulin on IpH6.0 with an EC50 value of 142.6 ± 11.7 nM. Each point represents the mean ± S.E.M. of 8–10 cells from 5–6 rats.
