Free radical mediated photoreceptor damage in uveitis

Rao, N. Purnachandra; Wu, Guey-Shuang

doi:10.1016/s1350-9462(99)00003-8

Cited by 69 publications

(44 citation statements)

References 91 publications

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“…The loss of vision is the result of damage inflicted by the infiltration of inflammatory cells into the retina, which is facilitated by the disruption of the blood-retinal barrier. 30 The retina is considered to be the most susceptible tissue to oxidative stress. This may be due to the following reasons: the presence of abundant mitochondria, 31 which consume large amounts of oxygen and the presence of photosensitive retinal pigments.…”

Section: Discussionmentioning

confidence: 99%

Increased homocysteine, homocysteine-thiolactone, protein homocysteinylation and oxidative stress in the circulation of patients with Eales’ disease

et al. 2013

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Background: Eales' disease (ED) is an idiopathic retinal vascular disorder. It presents with inflammation and neovascularization in the retina. Adult men, aged between 15 and 40 years are more susceptible than women. Homocysteine has been implicated in other ocular diseases including age-related macular degeneration (ARMD), central retinal vein occlusion (CRVO) and optic neuropathy. The present study investigates the role of homocysteine in ED. Methods: Forty male subjects, 20 with ED and 20 healthy controls, were recruited to the study. Their blood samples were used to measure thiobarbituric acid reactive substances (TBARS), glutathione (GSH), homocysteine, homocysteine-thiolactone, extent of homocysteine conjugation with proteins and plasma copper concentration. Results: In the ED group, plasma homocysteine (18.6 AE 1.77 mmol/L, P < 0.001) and homocysteine-thiolactone (45.3 AE 6.8 nmol/L, P < 0.0001) concentrations were significantly higher compared to homocysteine (11.2 AE 0.64 mmol/L) and homocysteine-thiolactone (7.1 AE 0.94 nmol/L) concentrations in control subjects. TBARS (P < 0.011) and protein homocysteinylation (P < 0.030) were higher in the ED group while GSH (5.9 AE 0.44 mmol/L, P < 0.01) and copper (6.6 AE 0.42 mmol/L, P < 0.001) were lower compared to GSH (8.1 AE 0.41 mmol/L) and copper (15.4 AE 0.73 mmol/L) concentrations in control subjects. Conclusions: Increased homocysteine, and its metabolite thiolactone, is associated with the functional impairment of protein due to homocysteinylation in ED.

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Section: Discussionmentioning

confidence: 99%

Increased homocysteine, homocysteine-thiolactone, protein homocysteinylation and oxidative stress in the circulation of patients with Eales’ disease

et al. 2013

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“…ROS are active components of the phagocytic system of PMNL [39]. In the event of neutrophils and macrophages becoming stimulated by pathogens, cytokines or other inflammation mediators are liberated from the granula into the cytoplasm [40].…”

Section: Discussionmentioning

confidence: 99%

Effects of Vitamin E, Pentoxifylline and Aprotinin on Light-Induced Retinal Injury

Yılmaz

Aydemir²,

Özercan³

et al. 2007

Ophthalmologica

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Purpose: A considerable amount of clinical and experimental evidence exists suggesting the involvement of reactive oxygen species (ROS) in the etiology of light-induced retinal injury. The aim of this study was to investigate the protective role of vitamin E, pentoxifylline (PTX) and aprotinin against light-induced retinal injury in guinea pigs. Methods: Thirty adult male guinea pigs were divided into 5 groups of 6 animals each. The first group was used as control. The guinea pigs were kept in cyclic light for 2 weeks before the experiments. The animals were maintained in 12-hour light-dark cycles, before and after exposure to intense white fluorescent light, for as long as 12 h and then returned to cyclic light. Groups 3–5 received intraperitoneal injections of vitamin E, PTX and aprotinin, respectively. One eye of each animal was selected for histopathological evaluation and the other for biochemical assay. Retinal malondialdehyde (MDA) levels and the thickness of the outer nuclear layers were measured. Results: The compounds had the following relationships: vitamin E more than PTX more than aprotinin in preventing light-induced retinal damage. All 3 gave significant protection against the formation of MDA. Retinas of all 3 treatment groups had been protected from light-induced injury. Conclusion: The intraperitoneal vitamin E, PTX and aprotinin supplementations may strengthen the antioxidant defense system because of decreased ROS, and these agents may play a role in treating light-induced retinal injury.

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“…The processes can extend, however, to involve the retina, intraoculer cavities, optic nerve and other optic structures. 1 Chronic intraoculer inflammation is a major cause of blindness. This loss of vision is the result of damage inflicted by inflammatory cell infiltration, particularly the release of various mediators including oxygen metabolites.…”

Section: Introductionmentioning

confidence: 99%

“…This loss of vision is the result of damage inflicted by inflammatory cell infiltration, particularly the release of various mediators including oxygen metabolites. 1,2 In uveitis, the primary inflammatory cellular infiltration consists of an admixture of phagocytes and various types of lymphocytes. 3 The former includes polymorphonuclear leucocytes (PMN) and macrophages, which on activation are known to generate reactive oxygen substances (ROS).…”

Section: Introductionmentioning

confidence: 99%

“…[4][5][6] ROS can cause severe membrane injury by initiating various reactions, including lipid peroxidations, which may alter membrane integrity and permeability characteristics. 1 The outer segments of retinal photoreceptors have a high content of long-chain unsaturated fatty acids, which render the retina very susceptible to oxidative damage. 7 Oxidative damage to retinal cells adversely affects their normal physiology and may lead to sight-threatening ocular diseases.…”

Section: Introductionmentioning

confidence: 99%

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Protective effects of intraperitoneal vitamin C, aprotinin and melatonin administration on retinal edema during experimental uveitis in the guinea pig

Kükner

Nazıroğlu

Çolakoğlu

et al. 2004

Cell Biochemistry & Function

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A considerable amount of clinical and experimental evidence exists suggesting the involvement of reactive oxygen substances (ROS) in the aetiology of uveitis. The activated phagocytic system of polymorphonuclear leucocytes in uveitis is involved in the generation of ROS. In addition to their direct free radical scavenging action, aprotinin, melatonin and vitamin C are known to protect against oedema formation and can preserve plasma membrane fluidity and free radical production. Histological changes in the retina that occur during uveitis are not well explained. The purpose of this study was to determine whether vitamin C, aprotinin and melatonin can protect the retina from damage accompanying experimental uveitis (EU). Thirty adult male guinea pigs were divided into five groups of six animals each. The first group was used as control. The right eyes of groups 2, 3, 4 and 5 received an intravitreal injection of bovine serum albumin for induction of experimental uveitis. At the same time and also on the consecutive third day, groups 3, 4 and 5 received intraperitoneal injections of vitamin C (ascorbic acid, 100 mg kg(-1) body wt), aprotinin (20,000 kIU kg(-1) body wt) and melatonin (10 mg kg(-1) body wt), respectively. The animals were killed on the sixth day. The average thickness of the retina and inner plexiform layer for each eye was measured in sagittal section near the optic nerve and expressed in microns. The thickness of the retina and inner plexiform layer in the control group was significantly (p < 0.01) lower than in the group EU as compared with the group EU plus vitamin C, group EU plus aprotinin, group EU plus melatonin (p < 0.05). The thicknesses of the retina and inner plexiform layer in group EU plus vitamin C, group EU plus aprotinin and group EU plus melatonin were significantly (p < 0.01) lower than that in the group EU. The difference in thickness of the retina and inner plexiform layer among the groups 3, 4 and 5 was not significant (p > 0.05). In conclusion, this study demonstrated that oedematous effects of EU on the retina were reduced by the administration of intraperitoneal vitamin C, aprotinin and melatonin, i.e. these antioxidants had significant protective effects on the retina of guinea pigs against oedematous damage in EU. However, the reductive effect of vitamin C on EU was greater than that of aprotinin and melatonin. The intraperitoneal vitamin C, aprotinin and melatonin supplementations may strengthen the antioxidant defence system because of decreased ROS, and these agents may play a role in treating uveitis.

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Free radical mediated photoreceptor damage in uveitis

Cited by 69 publications

References 91 publications

Increased homocysteine, homocysteine-thiolactone, protein homocysteinylation and oxidative stress in the circulation of patients with Eales’ disease

Increased homocysteine, homocysteine-thiolactone, protein homocysteinylation and oxidative stress in the circulation of patients with Eales’ disease

Effects of Vitamin E, Pentoxifylline and Aprotinin on Light-Induced Retinal Injury

Protective effects of intraperitoneal vitamin C, aprotinin and melatonin administration on retinal edema during experimental uveitis in the guinea pig

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