1. Time-dependent effects of IL-6 on tyrosine phosphorylation of IRS-1.
Time-dependent effects of IL-6 on tyrosine phosphorylation of IRS-1. Confluent HepG2 cells were treated as in Fig. 1. IRS-1 was immunoprecipitated, separated by SDS-PAGE, and subjected to Western blot analysis with an antiphosphotyrosine antibody (Upstate Biological). A comparable IRS-1 immunoprecipitate from 0.5 nmol/l insulin-treated cells was probed for IRS-1 mass. Results were visualized by enhanced chemiluminescence (Amersham Pharmacia). Representative blots of three independent experiments are shown. The 0.5 nmol/l blot required longer exposure times to obtain comparable signal intensity to the 100 nmol/l insulin blot. The data for 0.5 nmol/l insulin from the three experiments were quantitated by densitometry and expressed as percent of initial ± SD (no IL-6, time zero). *P < 0.01 and **P < 0.05 as compared with control (no IL-6, time zero).
Joseph J. Senn et al. Diabetes 2002;51:
©2002 by American Diabetes Association