Figure 1. Elevated glucose does not alter the composition of AMPA (α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid) receptors in cultured retinal neural cells. Cells were exposed to 30 mM glucose (Gluc) or 25 mM mannitol (Man - osmotic control; + 5 mM glucose) for 48 h. The interaction between AMPA receptor subunits was analyzed with coimmunoprecipitation (IP) followed by western blotting (WB). A: Immunoreactivity of GluA2 and GluA4 in the immunoprecipitated samples of GluA1. B: Immunoreactivity of GluA1 and GluA4 in the immunoprecipitated samples of GluA2. C: Immunoreactivity of GluA1 and GluA2 in the immunoprecipitated samples of GluA4. The results are presented as mean ± standard error of the mean (SEM) of at least three independent experiments and are expressed as a percentage of the control. Representative immunoblots are presented on the right of the respective graphs.