Fig. 7. Depletion of PRODH blocks the synthesis of amino acids from proline in the RPE and its export into the retina.

(A) A schematic of in vivo tracing of ¹⁵N proline. Mice were fasted for 18 hours and received two injections of ¹⁵N proline (150 mg/kg) at 0 min and 10 min, respectively. Retina and RPE/Cho were harvested at 30min after the second injection for metabolite analysis with GC MS. (B) Prodh −/− blocks the synthesis of amino acids from ¹⁵N proline in the RPE and its export into the retina. (C-K) ¹⁵N fraction of metabolites derived from ¹⁵N proline in RPE/Cho and retina. N=6.