Subscribe to RSS
DOI: 10.1055/s-2001-15895
Georg Thieme Verlag Stuttgart · New York
Abhängigkeit der Lipidperoxidation von der Pigmentierung porkiner Iris
Dependence of lipid peroxidation on pigmentation in porcine irisPublication History
Publication Date:
31 December 2001 (online)
![](https://www.thieme-connect.de/media/klimo/200105/lookinside/thumbnails/10.1055-s-2001-15895-1.jpg)
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 - 02 Young R W. Solar radiation and age related macular degeneration. Surv Ophthalmol. 1988;; 32 252-269
- 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
- 04 Schumer R A, Podos S M. The nerve of glaucoma!. Arch Ophthalmol. 1994;; 112 (1) 37-44
- 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
- 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
- 07 Spector A. Oxidative stress-induced cataract: mechanism of action. FASEB J. 1995;; 9 (12) 1173-1182
- 08 Anderson R E, Kretzer F L, Rapp L M. Free radicals and ocular disease. Adv Exp Med Biol. 1994;; 366 73-86
- 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
- 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
- 11 Sies H (ed). Oxidative Stress, Oxidants and Antioxidants. Academic Press; New York; 1991.:
- 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
-
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 - 14 Ezzahir A. The influence of Melanins on the Photoperoxidation of Lipids. J Photochem Photobiol, B: Biology. 1989;; 3 341-349
- 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
- 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
-
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 - 18 Asakawa T, Matsushita S. Thiobarbituric acid test for detecting lipid hydroperoxides under anaerobic condition. Agr Biol Chem. 1981;; 45 (2) 453-457
- 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
- 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
- 21 Murti G SRK, Moharir A V, Sarma V AK. Spectrophotometric determination of iron with orthophenantroline. Microchem J. 1970;; 15 585-589
- 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
- 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
- 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
- 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
- 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
- 27 Hammond B R Jr, Fuld K, Snodderly D M. Iris colour and macular pigment optical density. Exp Eye Res. 1996;; 62 293-297
- 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
- 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
- 30 Eye Case-Control Study Group. Risk factors for neovascular age-related macular degeneration. Arch Ophthalmol. 1992;; 110 1701-1708
- 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
- 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
- 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
- 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
- 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