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Klin Monbl Augenheilkd 2001; 218(5): 341-344
DOI: 10.1055/s-2001-15895
EXPERIMENTELLE STUDIE

Georg Thieme Verlag Stuttgart · New York

Abhängigkeit der Lipidperoxidation von der Pigmentierung porkiner Iris

Dependence of lipid peroxidation on pigmentation in porcine irisKerstin Nau-Staudt1 , Werner  M. Nau2 , Ivan  O. Haefliger1 , Josef Flammer1
  • 1 Universitäts-Augenklinik, Labor für okuläre Pharmakologie und Physiologie, Mittlere Straße 91, CH-4056 Basel (Dir.: Prof. Dr. J. Flammer), E-mail: kerstin.nau@unibas.ch
  • 2 Departement Chemie, Universität Basel, Klingelbergstraße 80, CH-4056 Basel
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Publication History

Publication Date:
31 December 2001 (online)

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Zusammenfassung

Hintergrund Lipidperoxidationsstudien haben gezeigt, dass Melanin antioxidativ wirkt. Wir haben nun die Abhängigkeit der Lipidperoxidation von der stromalen Pigmentierung in isoliertem porkinen Irisgewebe untersucht.

Material und Methoden Die gleiche Anzahl gering (weißlich) und stark pigmentierter Irisen (dunkelbraun; visuell ausgewählt) wurde in Puffer homogenisiert (50 mmol/l Na2HPO4, 50 mmol/l NaH2PO4 und 4 mmol/l Natriumazid; 1 : 20 w/v). Jeweils 500 μl Homogenisat wurden bei 37 °C für 5, 10, 20 und 40 min in Ab- und Anwesenheit von Fe2+, einem Induktor der Lipidperoxidation, inkubiert. Das Ausmaß an Lipidperoxidation wurde mit Hilfe des Thiobarbitursäure-(TBA)-Tests ermittelt. Die Ergebnisse wurden in nmol TBA-reaktives Material (TBAR)/mg Protein umgerechnet. Die Fe2+-Konzentration der Inkubationslösung wurde spektrophotometrisch mit Phenanthrolin bestimmt.

Ergebnisse 70 μmol/l, 180 μmol/l und 360 μmol/l Fe2+ induzierten Lipidperoxidation. Nach 20 min wurde ein Plateau erreicht. Es zeigte sich, dass sich die Lipidperoxidation in porkinen Irisen in Abhängigkeit von der stromalen Pigmentierung um den Faktor 2,8 unterschied. In Gegenwart von 180 μmol/l Fe2+ wurden nach einer Inkubationszeit von 10 min in gering pigmentiertem Irisgewebe 1,373 ± 0,138 nmol TBAR/mg Protein induziert, in stark pigmentiertem Irisgewebe dagegen nur 0,491 ± 0,125 nmol TBAR/mg Protein (p < 0,0001, n=4). Andererseits unterschied sich der Gehalt an Fe2+ in der Inkubationslösung nicht signifikant.

Schlussfolgerungen Die Lipidperoxidation wurde in gering pigmentiertem porkinen Irisgewebe stärker induziert als in stark pigmentiertem Irisgewebe. Dieser Effekt ist vermutlich auf den unterschiedlichen Gehalt an Melanin und dessen Antioxidansaktivität zurückzuführen.

Purpose Melanin has been shown to act as antioxidant in lipid peroxidation studies. We have now investigated lipid peroxidation in dependence on stromal pigmentation in isolated porcine irises.

Methods The same number of lightly pigmented and heavily pigmented porcine irises (visual selection) were homogenized in buffer (50 mmol/l Na2HPO4, 50 mmol/l NaH2PO4 and 4 mmol/l sodium azide; 1 : 20 w/v). 500 μl homogenate were incubated at 37 oC for 5, 10, 20 and 40 min in absence and presence of Fe2+ as inducer of lipid peroxidation. Lipid peroxidation was assayed by the thiobarbituric acid (TBA) test. Results are expressed as nmol of TBA reactive material produced (TBAR) per mg protein. Fe2+ concentration of the supernatant was determined spectrophotometrically with phenanthroline.

Results 70 μmol/l, 180 μmol/l and 360 μmol/l Fe2+ induced lipid peroxidation. A plateau region was reached after 20 min. Lipid peroxidation differed in dependence on stromal pigmentation in porcine irises by a factor of 2.8. 180 μmol/l Fe2+ induced 1.373 ± 0.138 nmol TBAR/mg protein in lightly pigmented irises compared to 0.491 ± 0.125 nmol TBAR/mg protein in heavily pigmented irises after 10 min incubation (p < 0.0001, n=4). On the other hand, the content of Fe2+ in the supernatant was the same within error.

Conclusions There was a stronger induction of lipid peroxidation in lightly pigmented porcine irises compared to heavily pigmented porcine irises. This effect may be related to the difference in stromal melanin content and its antioxidant activity.

Schlüsselwörter

Lipidperoxidation - oxidativer Stress - Iris - Pigmentierung - altersabhängige Makuladegeneration

Key words

Lipid peroxidation - oxidative stress - iris - pigmentation - age-related macular degeneration

Literatur

  • 01 Pryor  W A. The free radical theory of aging revisited: a critique and a specific disease-specific theory. In: Butler RN, Sprott RL, Schneider EL, eds. Modern biological theories of aging. Raven Press, New York; 1987;: 42-63
    Google Scholar
  • 02 Young  R W. Solar radiation and age related macular degeneration.  Surv Ophthalmol. 1988;;  32 252-269
    Google Scholar
  • 03 De La Paz  M A, Anderson  R E. Regional and age-dependent variation in susceptibility of the human retina to lipid peroxidation.  Invest Ophthalmol Vis Sci. 1992;;  33 3497-3499
    Google Scholar
  • 04 Schumer  R A, Podos  S M. The nerve of glaucoma!.  Arch Ophthalmol. 1994;;  112 (1) 37-44
    Google Scholar
  • 05 Yan  D B, Trope  G E, Ethier  C R, Menon  I A, Wakeham  A. Effects of hydrogen peroxide-induced oxidative damage on outflow facility and washout in pig eyes.  Invest Ophthalmol Vis Sci. 1991;;  32 (9) 2515-2520
    Google Scholar
  • 06 Zaretskaya  R B, Trutneva  K V, Suprun  A V, Ostrovskaya  R U, Shmaryan  M I. Effect of antihypoxant-sodium hydroxybutyrate on visual functions and oxidative processes in glaucoma patients.  Metab Pediatr Syst Ophthalmol. 1983;;  7 (4) 189-194
    Google Scholar
  • 07 Spector  A. Oxidative stress-induced cataract: mechanism of action.  FASEB J. 1995;;  9 (12) 1173-1182
    Google Scholar
  • 08 Anderson  R E, Kretzer  F L, Rapp  L M. Free radicals and ocular disease.  Adv Exp Med Biol. 1994;;  366 73-86
    Google Scholar
  • 09 Varma  S D, Chand  D, Sharma  Y R, Kuck  J F Jr, Richards  R D. Oxidative stress on lens and cataract formation: role of light and oxygen.  Curr Eye Res. 1984;;  3 (1) 35-57
    Google Scholar
  • 10 Bhuyan  K C, Bhuyan  D K. Molecular mechanism of cataractogenesis: III. Toxic metabolites of oxygen as initiators of lipid peroxidation and cataract.  Curr Eye Res. 1984;;  3 (1) 67-81
    PubMedGoogle Scholar
  • 11 Sies  H (ed). Oxidative Stress, Oxidants and Antioxidants. Academic Press; New York; 1991.:
    Google Scholar
  • 12 Zhang  X, Erb  C, Flammer  J, Nau  W M. Absolute Rate Constants for the Quenching of Reactive Excited States by Melanin and related 5,6-Dihydroxyindole Metabolites: Implications for their antioxidant activity.  Photochem Photobiol. 2000;;  71 (5) 524-533
    CrossrefPubMedGoogle Scholar
  • 13 Sealy  R C, Felix  C C, Hyde  J S, Swartz  H M. Structure and Reactivity of Melanins: Influence of Free Radicals and Metal Ions. In: Free Radicals in Biology. Pryor WA, ed. Academic Press, New York; 1980;: 209-259
    Google Scholar
  • 14 Ezzahir  A. The influence of Melanins on the Photoperoxidation of Lipids.  J Photochem Photobiol, B: Biology. 1989;;  3 341-349
    PubMedGoogle Scholar
  • 15 Bustamante  J, Bredeston  L, Malanga  G, Mordoh  J. Role of Melanin as a Scavenger of Active Oxygen Spezies.  Pigment Cell Res. 1993;;  6 348-353
    PubMedGoogle Scholar
  • 16 Scalia  M, Geremia  E, Corsaro  C, Santoro  C, Baratta  D, Sichel  G. Lipid peroxidation in pigmented and unpigmented liver tissues: protective role of melanin.  Pigment Cell Res. 1990;;  3 115-119
    PubMedGoogle Scholar
  • 17 Buege  J A, Aust  S D. Microsomal lipid peroxidation. In: Methods in Enzymology. Biomembranes. Part C. Fleischer S. and Packer L., eds. Vol. 52,. Academic Press, New York and London; 1978;: 302-310
    Google Scholar
  • 18 Asakawa  T, Matsushita  S. Thiobarbituric acid test for detecting lipid hydroperoxides under anaerobic condition.  Agr Biol Chem. 1981;;  45 (2) 453-457
    PubMedGoogle Scholar
  • 19 Pikul  J, Lesczynski  D E, Kummerow  F A. Elimination of sample autoxidation by butylated hydroxytoluene additions before thiobarbituric acid assay for malonaldehyde in fat from chicken meat.  J Agric Food Chem. 1983;;  31 1338-1342
    CrossrefPubMedGoogle Scholar
  • 20 Lowry  O H, Rosenbrough  N J, Farr  A L, Randall  R J. Protein measurement with the Folin phenol reagent.  J Biol Chem. 1951;;  193 265-275
    PubMedGoogle Scholar
  • 21 Murti  G SRK, Moharir  A V, Sarma  V AK. Spectrophotometric determination of iron with orthophenantroline.  Microchem J. 1970;;  15 585-589
    CrossrefPubMedGoogle Scholar
  • 22 Janero  D R. Malondialdehyde and thiobarbituric acid-reactivity as diagnostic indices of lipid peroxidation and peroxidative tissue injury.  Free Rad Biol Med. 1990;;  9 515-540
    CrossrefPubMedGoogle Scholar
  • 23 Gelatt  K N, Rempel  W E, Makambera  T B, Anderson  J F. Heterochromia irides in miniature swine.  J Hered. 1973;;  64 (6) 343-347
    PubMedGoogle Scholar
  • 24 Imesch  P D, Wallow  I HL, Albert  D M. The colour of the human eye: A review of morphologic correlates and of some conditions that affect iridial pigmentation.  Surv Ophthalmol. 1997;;  41 (Suppl 2) 117-123
    PubMedGoogle Scholar
  • 25 Menon  I A, Wakeham  D C, Persad  S D, Avaria  M, Trope  G E, Basu  P K. Quantitative determination of the melanin contents of ocular tissues from human blue and brown eyes.  J Ocular Pharmacol. 1992;;  8 35-42
    PubMedGoogle Scholar
  • 26 Beatty  S, Boulton  M, Henson  D, Koh  H H, Murray  I J. Macular pigment and age related macular degeneration.  Br J Ophtalmol. 1999;;  83 867-877
    PubMedGoogle Scholar
  • 27 Hammond  B R Jr, Fuld  K, Snodderly  D M. Iris colour and macular pigment optical density.  Exp Eye Res. 1996;;  62 293-297
    CrossrefPubMedGoogle Scholar
  • 28 Frank  R N, Rajesh  H A, Puklin  J E. Antioxidant enzymes in the macular pigment epithelium of eyes with neovascular age-related macular degeneration.  Am J Ophthalmol. 1999;;  127 (6) 694-709
    CrossrefPubMedGoogle Scholar
  • 29 Hyman  L G, Lilienfeld  A M, Ferries  F L III, Fine  S L. Senile macular degeneration: a case control study.  Am J Epidemiol. 1983;;  118 213-227
    PubMedGoogle Scholar
  • 30 Eye  Case-Control Study Group. Risk factors for neovascular age-related macular degeneration.  Arch Ophthalmol. 1992;;  110 1701-1708
    PubMedGoogle Scholar
  • 31 Weiter  J J, Delori  F C, Wing  G L, Fitch  K A. Relationship of senile macular degeneration to ocular pigmentation.  Am J Ophthalmol. 1985;;  99 185-187
    PubMedGoogle Scholar
  • 32 Stock  C J, Canter  L A, Puklin  J E, Frank  R N. Gender, race, iris colour, and age-related macular degeneration.  Invest Ophthalmol Vis Sci. 1995;;  36 (Suppl) S10
    PubMedGoogle Scholar
  • 33 Holz  F G, Piguet  B, Minassian  D C, Bird  A C, Weale  R A. Decreasing stromal iris pigmentation as a risk factor for age-related macular degeneration.  Am J Ophthalmol. 1994;;  117 19-23
    PubMedGoogle Scholar
  • 34 Friedman  D S, Katz  J, Bressler  N M, Rahmani  B, Tielsch  J M. Racial differences in the prevalence of age-related macular degeneration.  Ophthalmology. 1999;;  106 1049-1055
    CrossrefPubMedGoogle Scholar
  • 35 Sandberg  M A, Gaudio  A R, Miller  S, Weisner  A. Iris pigmentation and extent of disease in patients with neovascular age-related macular degeneration.  Invest Ophthalmol Vis Sci. 1994;;  35 2734-2740
    PubMedGoogle Scholar