Maki Kamegawa

Showa University

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Takako Nakanishi‐Ueda

Showa University

Hajime Yasuhara

Nara Medical University

Katsuji Oguchi

Showa University

Donald Armstrong

Defence Science and Technology Laboratory

Ryohei Koide

Saga University

Shinichi Iwai

Showa University

Toshihiko Ueda

St. Marianna University School of Medicine

Masahiro Inagaki

Gifu Heart Center

Hirotsugu Ogura

Tokyo Institute of Technology

Keiko Sasuga

Jikei University School of Medicine

Cooperative Institutions

Showa University

Ophthalmology Associates (United States)

University of Florida

University at Buffalo, State University of New York

Maastricht University

Hospital General de México

Florida College

Maastricht University Medical Centre

Universidad Nacional Autónoma de México

Hacettepe University

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Appointment of New Section Editors

Ophthalmic Research (2006)

Maki Kamegawa Takako Nakanishi‐Ueda Shinichi Iwai Toshihiko Ueda Shotaro Kosuge

Section (typography)

10.1159/000097900

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Inhibitory Effect of Lutein and Pycnogenol on Lipid Peroxidation in Porcine Retinal Homogenate

Journal of Clinical Biochemistry and Nutrition (2006)

Takako Nakanishi‐Ueda Maki Kamegawa Seiichiro Ishigaki Masahiko Tsukahara Satoshi Yano

This study aimed to investigate the antioxidant effect of lutein, human macula pigment, and pycnogenol, which contains several flavonoids, on lipid peroxidation induced in 10% porcine retinal homogenate by the addition of 1 mM Ferric chloride (FeCl3), 50 mM 2,2'-azobis (2-amidino-propane) dihydrochloride (AAPH), or 25 mM 2,2'-azobis (2,4-dimethyl-valeronitrile) (AMVN). Lipid hydroperoxide concentration was determined from the amount of thiobarbituric acid reactive substances (TBARS) in the sample following treatment. After 60 min of oxidation with FeCl3, AAPH and AMVN, the TBARS content in the retinal homogenates increased from 28.6 ± 1.6 to 85.4 ± 0.9, from 27.9 ± 1.2 to 57.2 ± 1.1, and from 26.0 ± 1.0 to 77.5 ± 2.0 nmol MDA/mg protein, respectively. Lutein did not show remarkable antioxidant activity in this experimental system. However, IC50 of pycnogenol for TBARS formation was decreased by combining 10 μM lutein in each initiator; from 12 to 5 μg/mL in FeCl3, from 2.8 to 0.5 μg/mL in AAPH, from 465 to 110 μg/mL in AMVN. These results suggested that a combination treatment of lutein and pycnogenol is more effective for inhibiting lipid peroxidation in porcine retinal homogenate. This synergy might be due to efficient functional antioxidants acting in both hydrophilic and lipophilic cellular environments.

TBARS

Thiobarbituric acid

10.3164/jcbn.38.204

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Effect of Lipid-Hydroperoxide-Induced Oxidative Stress on Vitamin E, Ascorbate and Glutathione in the Rabbit Retina

Ophthalmic Research (2006)

Maki Kamegawa Takako Nakanishi‐Ueda Shinichi Iwai Toshihiko Ueda Shotaro Kosuge

It is possible that oxidative stress causes several retinal diseases. However, the natural biogenic role of antioxidants in the retina is not clear.This study investigates the change in concentration of vitamin E (VE), ascorbate and glutathione (GSH) in the retina following vitreous injection of 600 mug 18:2 linoleic acid hydroperoxide (LHP) in male New Zealand rabbits.LHP was injected above the retinal surface. The animals were sacrificed and the eyes enucleated before LHP injection, 1, 3, 6, 12, 24 h and 4 and 7 days after LHP injection. Retinas were removed, VE and ascorbate measured by HPLC, and GSH determined by a fluorometric method.The concentration of VE in the retina decreased from pretreatment levels of 154.6 +/- 29.7 nmol/g wet weight (n = 7) and was lowest at 6 h (61.1 +/- 18.1 nmol/g wet weight, n = 4, p < 0.05), then increased gradually, returning slowly to pre-LHP levels by 7 days. The concentration of ascorbate in control retinas decreased at 6 h from pretreatment levels of 7.33 +/- 0.93 micromol/g wet weight (n = 7) to 2.74 +/- 0.16 micromol/g wet weight (n = 4, p < 0.05) and returned to pretreatment levels rapidly by 24 h after injection. The concentration of GSH in retinas decreased from baseline levels of 109.53 +/- 8.19 microg/g wet weight (n = 9), was lowest at 12 h (72.40 +/- 11.17 microg/g wet weight, n = 5, p < 0.05) and returned to pretreatment levels by 7 days.The results suggest that intravitreous LHP injection is a contributor to oxidative stress in the rabbit retina by causing a reduction in antioxidant capacity.

10.1159/000097907

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Activation of AP-1 and Increased Synthesis of MMP-9 in the Rabbit Retina Induced by Lipid Hydroperoxide

Current Eye Research (2006)

Shinichi Iwai Ahmad Aljada Akira Higa Takako Nakanishi‐Ueda Shohei Fukuda

Purpose: We identified the temporal expression of activator protein-1 (AP-1) and matrix metalloproteinases (MMPs) after linoleic acid hydroperoxide (LHP) induction of retinal neovascularization. Methods: After injection of LHP into the vitreous of rabbits, samples were collected for AP-1 binding activity and mRNA for MMP-9 and MMPs activity. AP-1 binding activity was measured by eletrophoretic mobility shift assay. MMP-9 activity was measured by zymography and mRNA by quantitative RT-PCR. Results: AP-1 binding activity was increased at 1–3 hr. MMP-9 mRNA levels were increased at 3 hr in the neural retina and by 12 hr in the retinal pigment epithelium (RPE) layer. MMP-9 proteolytic activity was elevated within the neural retina and within the vitreous and in the RPE-interphotoreceptor matrix (IPM) at 12 hr and peaked at 24 hr or 4 days. Conclusions: LHP increases the transcription factor AP-1 which in turn may regulate retinal MMP-9 synthesis during neovascularization.

Zymography

10.1080/02713680600577780

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Citations (14)