title: Effect of UV-A and UV-B irradiation on the metabolic profile of aqueous humor in rabbits analyzed by 1H NMR spectroscopy.
abstract: OBJECTIVE
  This study was conducted to investigate metabolic changes in aqueous humor from rabbit eyes exposed to either UV-A or -B radiation, by using (1)H nuclear magnetic resonance (NMR) spectroscopy and unsupervised pattern recognition
  
  
  METHODS
  methods. Both eyes of adult albino rabbits were irradiated with UV-A (366 nm, 0.589 J/cm(2)) or UV-B (312 nm, 1.667 J/cm(2)) radiation for 8 minutes, once a day for 5 days. Three days after the last irradiation, samples of aqueous humor were aspirated, and the metabolic profiles analyzed with (1)H NMR spectroscopy. The metabolic concentrations in the exposed and control materials were statistically analyzed and compared, with multivariate methods and one-way ANOVA.
  
  
  RESULTS
  UV-B radiation caused statistically significant alterations of betaine, glucose, ascorbate, valine, isoleucine, and formate in the rabbit aqueous humor. By using principal component analysis, the UV-B-irradiated samples were clearly separated from the UV-A-irradiated samples and the control group. No significant metabolic changes were detected in UV-A-irradiated samples.
  
  
  CONCLUSIONS
  This study demonstrates the potential of using unsupervised pattern recognition methods to extract valuable metabolic information from complex (1)H NMR spectra. UV-B irradiation of rabbit eyes led to significant metabolic changes in the aqueous humor detected 3 days after the last exposure.
authors.affiliation: Faculty of Medicine, Norwegian University of Science and Technology, Trondheim, Norway. may-britt.tessem@medisin.ntnu.no
authors.forename: May-Britt
authors.initials: MB
authors.lastname: Tessem
authors.forename: Tone F
authors.initials: TF
authors.lastname: Bathen
authors.forename: Jitka
authors.initials: J
authors.lastname: Cejková
authors.forename: Anna
authors.initials: A
authors.lastname: Midelfart
mesh_terms: D000596:Amino Acids / Q000378:metabolism; D000818:Animals; D001082:Aqueous Humor / Q000378:metabolism* / Q000528:radiation effects*; D001205:Ascorbic Acid / Q000378:metabolism; D005128:Eye Diseases / Q000378:metabolism*; D005947:Glucose / Q000378:metabolism; D019906:Nuclear Magnetic Resonance, Biomolecular; D011817:Rabbits; D011833:Radiation Injuries, Experimental / Q000378:metabolism*; D014466:Ultraviolet Rays
chemical_list: D000596:Amino Acids; D005947:Glucose; D001205:Ascorbic Acid