Figure 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 h and received two injections of ¹⁵N proline (150 mg/kg) at 0 min and 10 min, respectively. Retina and RPE/Cho were harvested at 30 min 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. Error bars represent SD. Cho, choroid; PRODH, proline dehydrogenase; RPE, proline dehydrogenase.