Corneal alanine metabolism demonstrated by NMR spectroscopy

This study confirms the feasibility of monitoring corneal metabolism of an amino acid using high resolution NMR spectroscopy. Alanine metabolism to lactate was detected in intact, freshly isolated rabbit corneas. Progressively decreasing alanine resonances were noted after 4-5 hours of incubation while increasing amounts of lactate were detected. No similar signal was noted in de-epithelialized tissue. This study demonstrates the ability of corneal epithelium to utilize alanine as a metabolic substrate. This technique may be useful to determine the essential amino acids and their optimal concentrations necessary to maintain corneal viability during storage.