Figure 3

Effects of pertussis toxin on H ₂ O ₂ generation and receptor autophosphorylation neurons stimulated with insulin. (A) PTX dose–response curve for receptor autophosphorylation in CGN exposed to 100 nM insulin for 10 min (black triangles, mean±SEM of 3 to 8 cultures, *P<0.05 vs. 100 nM insulin). (B) Left Y axis: time courses of H₂O₂ efflux from CGN exposed to control buffer (white squares, mean of 3 culture dishes), 2 mg/L PTX (light grey squares, mean of 3 culture dishes), 100 nM insulin (red squares, mean of 3 culture dishes), or 100 nM insulin plus 2 mg/L PTX (grey squares, mean of 3 culture dishes). Right Y axis: first time derivatives (rates) of H₂O₂ efflux from CGN exposed to 100 nM insulin (red line) or 100 nM insulin plus 2 mg/L PTX (black line). (C) Left Y axis: receptor autophosphorylation in CGN exposed to control buffer, 2 mg/L PTX, 100 nM insulin, or 100 nM insulin plus 2 mg/L PTX. Black columns represent the mean±SEM of values obtained from 3 to 8 cultures. *P<0.05 vs. control. ^# P<0.05 vs. insulin. Right Y axis: Areas under curves (AUC) of H₂O₂ efflux for 30 s from CGN exposed to control buffer, 2 mg/L PTX, 100 nM insulin, or 100 nM insulin plus 2 mg/L PTX. Red columns represent the mean±SEM of values obtained from 3 culture dishes. *P<0.05 vs. control. ^# P<0.05 vs. insulin.