Fig. 6.

Glutathione content in a 6-d-old neuron-rich primary culture after incubation with amino acids and/or dipeptides. The cells were incubated for 4 hr in MM+ containing glutamine (1 mm) and either cysteine plus glycine (open circles) or CysGly (closed circles) in the concentrations indicated or in MM+ containing glycine (1 mm) plus γGluCys (closed triangles) of varied concentration. Before the incubation the cellular glutathione content was 34.0 ± 1.5 nmol of GSx/mg of protein. The data represent triplicates ± SD. The experiment was repeated with comparable results using an independently prepared culture.