Analysis of immediate changes of water-soluble metabolites in alkali-burned rabbit cornea, aqueous humor and lens by high-resolution 1H-NMR spectroscopy.
OBJECTIVE
To investigate immediate changes in water-soluble metabolites of ocular tissue in alkali-burned eyes by using high-resolution 1H-NMR spectroscopy.


METHODS
Adult New Zealand rabbit eyes were burned with 1 M NaOH for 1 min. Normal eyes were used as control. Samples from aqueous humor and perchloric acid extracts of the cornea and lens were analyzed on a NMR spectrometer operating at 500 MHz for protons. Metabolites were quantified by comparing peak area with an added internal standard, TSP (3'-trimethylsilylpropinate-2,2,3,3-d4).


RESULTS
Alkali burn of corneal surface causes immediate changes in concentration of many water-soluble metabolites in the anterior segment. Even as far away as the lens a significant increase in lactate was found. Cornea showed a significant increase in glucose and a significant decrease in hypo-taurine concentration. Most changes were observed in aqueous humor, with significant increases in succinate, creatine, scyllo- and myo-inositol and a significant decrease in citrate concentration. Furthermore, a small decrease in ascorbate concentration in aqueous humor was observed.


CONCLUSIONS
The present study provides a valuable contribution to the knowledge of metabolic alterations in alkali-burned eyes. It shows that 1H-NMR spectroscopy is well suited for simultaneous qualitative and quantitative analysis of changes of metabolite concentrations in damaged tissues. This can help us to better evaluate and understand the biological alterations due to alkali burn.
Risa
Oystein
O
Faculty of Physics, Informatics and Mathematics, Norwegian University of Science and Technology (NTNU), Trondheim. oystein.risa@medisin.ntnu.no
Saether
Oddbjørn
O
Midelfart
Anna
A
Krane
Jostein
J
Cejková
Jitka
J
D000596:Amino Acids / Q000378:metabolism; D000818:Animals; D001082:Aqueous Humor / Q000378:metabolism*; D001205:Ascorbic Acid / Q000378:metabolism; D015415:Biomarkers; D002057:Burns, Chemical / Q000378:metabolism*; D050260:Carbohydrate Metabolism; D003315:Cornea / Q000187:drug effects / Q000378:metabolism*; D005126:Eye Burns / Q000139:chemically induced*; D007908:Lens, Crystalline / Q000378:metabolism*; D019906:Nuclear Magnetic Resonance, Biomolecular / Q000379:methods*; D009711:Nucleotides / Q000378:metabolism; D011817:Rabbits; D012972:Sodium Hydroxide / Q000633:toxicity; D012995:Solubility
D000596:Amino Acids; D015415:Biomarkers; D009711:Nucleotides; D012972:Sodium Hydroxide; D001205:Ascorbic Acid