Figure 1

Relationship between H ₂ O ₂ signal and receptor autophosphorylation in neurons stimulated with insulin. (A) Insulin dose–response for receptor autophosphorylation in CGN exposed to insulin for 10 min (black triangles, mean±SEM of 5 to 9 cultures, *P<0.05 vs. control). (B) Time course of receptor autophosphorylation in CGN exposed to 100 nM insulin (black triangles, mean±SEM of 3 to 4 cultures, *P<0.05 vs. baseline). (C) N-acetylcysteine dose–response for receptor autophosphorylation in CGN exposed to 100 nM insulin for 10 min (black triangles, mean±SEM of 3 to 7 cultures, *P<0.05 vs. 100 nM insulin). (D) Left Y axis: time courses of H₂O₂ efflux from CGN exposed to vehicle (white squares, mean of 3 culture dishes) or 100 nM insulin (red squares, mean of 10 culture dishes). Right Y axis: first time derivative (rate) of H₂O₂ efflux from CGN exposed to vehicle (black line) or 100 nM insulin (red line). (E) Areas under curves (AUC) for 30-s periods of H₂O₂ efflux from CGN exposed to vehicle (white columns, mean±SEM, n=3) or 100 nM insulin (red columns, mean±SEM, n=10, *P<0.05 vs. control). (F) Time courses for insulin-stimulated H₂O₂ efflux and receptor autophosphorylation. Left Y axis: time course of receptor autophosphorylation in CGN exposed to 100 nM insulin (black triangles, mean±SEM of 3 to 4 cultures). Right axis: first time derivative (rate) of H₂O₂ efflux from CGN exposed to 100 nM insulin (red line, mean of 10 culture dishes).