Figure 4.

Proline-derived amino acids appear later in the retina than the RPE/Cho.A, a schematic of in vivo tracing of ¹⁵N proline. Mice were fasted for 18 h and received a single injection of ¹⁵N proline (150 mg/kg) or PBS. Retina and RPE/Cho were harvested at 0, 5, 15, and 30 min after injection for metabolite analysis with GC–MS. B–H, ¹⁵N fraction of proline and metabolites derived from ¹⁵N proline in RPE/Cho and retina at different time points. N = 4. Error bars represent SD. Cho, choroid; RPE, retinal pigment epithelium.