Figure 4
Glutathione depletion via diethyl maleate (DEM) results in a significantly lower rate of [1-13C]dehydroascorbate (DHA) to [1-13C]vitamin C (VitC) conversion. Both apparent VitC production rate (kapp) and kinetic rate (k) of VitC production in the brain decreased significantly after DEM treatment (a,b), consistent with significantly lower brain GSH content in DEM-treated rats compared to control rats (c). To demonstrate DHA to VitC reaction order, 1D spectroscopy was performed on a separate cohort of rats with HP [1-13C]DHA at 60% of the usual dose. The average signal of [1-13C]DHA and [1-13C]VitC at each time point were plotted (d), and VitC signal appears unchanged with decreased DHA dose. The resulting kapp, k, and total 13C VitC SNR are not significantly different from the control group (e,f,g). (*p < 0.05, ****p < 0.0001).
