title: Biological response in various compartments of the rat lens after in vivo exposure to UVR-B analyzed by HR-MAS 1H NMR spectroscopy.
abstract: OBJECTIVE
  The purpose of the present study was to investigate metabolic changes in different compartments of the rat lens (anterior, nuclear, posterior, and equatorial) after exposure to an acute double threshold dose of ultraviolet-B radiation (UVR-B) by using high-resolution magic angle spinning (HR-MAS) (1)H nuclear magnetic resonance (NMR) spectroscopy and pattern recognition (PR) METHODS: methods. One eye in each of 28 6-week-old female albino Sprague-Dawley rats was exposed to in vivo 7.5 kJ/m2 UVR-B for 15 minutes. The contralateral eye was left unexposed. One week after irradiation, all rats were killed, and both lenses were isolated. Each lens was cored by a trephine, and the cylinder was sliced into three portions (anterior, nuclear, and posterior). The lens material that remained after the coring process was analyzed as the equatorial region. Analysis of lens metabolism was performed by HR-MAS 1H NMR spectroscopy (14.1 T; Avance DRX600; Bruker BioSpin GmbH, Rheinstetten, Germany), and the metabolic profiles were statistically analyzed by the PR method of principal component analysis (PCA).
  
  
  RESULTS
  Metabolic differences were detected among the compartments in the lens, both in samples from the contralateral nonexposed lenses and in samples from lenses exposed to in vivo UVR-B. In the rat lens, exposure to UVR-B caused changes in GSH, phosphocholine, myo-inositol, succinate, formate, and adenosine triphosphate (ATP)/adenosine diphosphate (ADP) and in levels of the amino acids phenylalanine, taurine, hypo-taurine, tyrosine, alanine, valine, isoleucine, and glutamate, that varied among lens compartments.
  
  
  CONCLUSIONS
  HR-MAS 1H NMR spectroscopy, combined with PR methods (PCA), is effective for analysis of separate parts of the intact rat lens. To understand the biochemistry of the lens, it is important to divide the lens into sections, representing functionally and anatomically distinct compartments.
authors.affiliation: Department of Neuroscience, Faculty of Medicine, Norwegian University of Science and Technology (NTNU), Trondheim, Norway. may.britt.tessem@ntnu.no
authors.forename: May-Britt
authors.initials: MB
authors.lastname: Tessem
authors.forename: Tone F
authors.initials: TF
authors.lastname: Bathen
authors.forename: Stefan
authors.initials: S
authors.lastname: Löfgren
authors.forename: Oddbjørn
authors.initials: O
authors.lastname: Saether
authors.forename: Vino
authors.initials: V
authors.lastname: Mody
authors.forename: Linda
authors.initials: L
authors.lastname: Meyer
authors.forename: Xiuqin
authors.initials: X
authors.lastname: Dong
authors.forename: Per G
authors.initials: PG
authors.lastname: Söderberg
authors.forename: Anna
authors.initials: A
authors.lastname: Midelfart
mesh_terms: D000244:Adenosine Diphosphate / Q000378:metabolism; D000255:Adenosine Triphosphate / Q000378:metabolism; D000596:Amino Acids / Q000378:metabolism; D000818:Animals; D003459:Crystallins / Q000378:metabolism*; D005260:Female; D005978:Glutathione / Q000378:metabolism; D007908:Lens, Crystalline / Q000378:metabolism* / Q000528:radiation effects*; D019906:Nuclear Magnetic Resonance, Biomolecular; D010767:Phosphorylcholine / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D014466:Ultraviolet Rays
chemical_list: D000596:Amino Acids; D003459:Crystallins; D010767:Phosphorylcholine; D000244:Adenosine Diphosphate; D000255:Adenosine Triphosphate; D005978:Glutathione