In recent years, a great number of studies have investigated the possible role of reactive oxygen species in the aetiology and pathogenesis of rheumatoid arthritis (RA). The aim of this study was to investigate plasma concentrations of vitamin E, beta-carotene, activities of glutathione peroxidase (GSH-Px) and catalase, levels of lipid peroxidation (MDA) and reduced glutathione (GSH) in 36 patients with rheumatoid arthritis (RA) and 22 healthy age-matched controls. The plasma activity of GSH-Px and catalase (p < 0.001), levels of GSH (p < 0.01), concentration of beta-carotene (p < 0.05) and vitamin E (p < 0.001), haemoglobin and hematocrit (p < 0.05) were significantly lower in patients with RA than in controls. The MDA levels (p < 0.01), C reactive protein, rheumatoid factor, anti-streptolysin-o values (p < 0.001), platelet count (p < 0.05) and erythrocyte sedimentation rate (p < 0.001) were higher in the patient group than in the control group. These results provide some evidence for a potential role of increased lipid peroxidation and decreased enzymic and non-enzymic antioxidants in RA by its inflammatory character. These results suggested that oxidant stress plays a very important role in the pathogenesis of RA.

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The aim of the study was to investigate the effects of testosterone propionate and vitamin E on the antioxidant system in the testis. Thirty-two male New Zealand White rabbits were randomly divided into four groups. The first group was used as control. The second group was injected with testosterone propionate, the third group vitamin E and the fourth group vitamin E and testosterone propionate combination. All treatments were carried out during 6 weeks and oxidative parameters were evaluated in homogenized testicular tissue. The levels of vitamin E and the activity of glutathione peroxidase were lower (P < 0.05) in the testosterone group than in controls. However, vitamin C and malondialdehyde levels were higher (P < 0.05) in this group than in controls. The levels of reduced glutathione, beta-carotene, vitamin C and E increased, but malondialdehyde levels decreased in the vitamin E group, when compared with controls (P < 0.05). Vitamin E and beta-carotene levels were significantly higher (P < 0.05) in the combination group than in testosterone group. However, MDA levels were lower (P < 0.05) in combination group than in the testosterone group. In conclusion, administration of testosterone propionate led to a significant elevation of oxidative stress. Vitamin E is quite an effective antioxidant which protects rabbit testis against lipid peroxidation, and, testosterone-induced lipid peroxidation could be improved by additional vitamin E treatment.

This study was conducted to evaluate the effects of dietary restriction on oxidative status and sperm parameters in rats exposed to long-term heat stress. Forty healthy Sprague-Dawley rats, aged 2.5 month, were divided into four groups of 10 with respect to feeding and temperature regimen (room temperature (22 °C)-ad libitum, room temperature-dietary restriction (40%), high temperature (38 °C)-ad libitum, high temperature-dietary restriction). At the end of the 9th week, some oxidants (lipid hydroperoxide, total oxidant status, oxidative stress index) and antioxidants (total antioxidant status, sulfhydryl groups, ceruloplasmin, paraoxonase and arylesterase activities) were measured in the testis tissue. The concentration, motility, volume, abnormal sperm count, acrosome and membrane integrity of epididymal spermatozoon and intratesticular testosterone levels were evaluated. High temperature did not change oxidative and antioxidative parameters except for sulfhydryl groups and ceruloplasmin, yet it impaired all sperm values. Neither sperm values nor oxidative status apart from sulfhydryl groups, ceruloplasmin and arylesterase was affected by dietary restriction in the testis tissue. These results suggest that long-term heat stress does not have a significant effect on testicular oxidative status, while the spermatozoa are sensitive to heat stress in young rats. Dietary restriction failed to improve the sperm quality and oxidative status except some individual antioxidant parameters; conversely, it decreased intratesticular testosterone level in the young rats exposed to long-term heat stress.

Özet: Bu çalışma, trafik kirliliğinin sığırlarda bazı hematolojik parametreler, lipid peroksidasyonu ve eritrosit ozmotik direnci üzerine etkilerinin araştırılması amacıyla yapıldı. Çalışmada ana yola 300 m uzaklıkta yaşayan (araştırma grubu, n=24) ve ana yola 2.5 km uzaklıkta yaşayan (kontrol grubu, n=14) toplam 38 baş sığır kullanıldı. Hayvanlardan alınan kan örneklerinde bazı kan parametreleri, eritrositte lipid peroksidasyonunun bir indikatörü olan malondialdehit (MDA) düzeyi ve eritrosit ozmotik direnci belirlendi. Araştırma grubunda bulunan hayvanlarda MDA düzeyinin daha yüksek olduğu (P<0.05) bulundu. Diğer parametrelerde ise gruplar arasında fark bulunamadı. Elde edilen sonuçlar trafik kirliliğinin eritrositlerde lipid peroksidasyonunu uyardığını, bununla birlikte kan parametreleri ve eritrosit zar direnci üzerine herhangi bir etkisinin bulunmadığını gösterdi. Abstract: The aim of this study was to evaluate the effects of traffic pollution on some haematological parameters, lipid peroxidation and osmotic resistance of erythrocyte in cattle. In the study, totally 38 cattle, living 300 m away (study group, n = 24) and 2.5 km away from the main road (control group, n = 14), were used. Some blood parameters, erythrocyte malondialdehyde (MDA) levels, an indicator of lipid peroxidation, and osmotic resistance were determined in the blood samples taken from the animals. MDA levels of the study group were significantly higher (P<0.05) than the control group. Other parameters of the study revealed no significant difference between groups. The results obtained showed that although traffic pollution induces lipid peroxidation in erythrocytes, while it has no considerable effects on blood parameters and erythrocyte membrane resistance in cattle.

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Reactive oxygen species have fundamental roles in reproductive functions. To comprehensively evaluate the relation between reactive oxygen species and infertility, physiological variations across the estrous cycle in healthy cows have to be known. For this purpose 25 healthy multiparous Holstein dairy cows having regular estrous cycles were used. The estrous cycles were synchronized by ovsynch protocol. Oxidant [lipid hydroperoxide (LOOH), total oxidant status (TOS), oxidative stress index (OSI)], antioxidant parameters [total antioxidant status (TAS), total free sulfhydryl groups (SH), ceruloplasmin (CP), paraoxonase-1 (PON1), arylesterase (ARE), uric acid (UA)], lipid profile and progesterone levels were assayed at estrus, metestrus, diestrus and proestrus stages of the estrous cycle in the plasma samples. The plasma levels of oxidant (LOOH, TOS and OSI) and antioxidant (TAS, SH and UA) parameters were significantly decreased during the luteal phase compared to the follicular phase (at proestrus and at estrus) of the estrous cycle. There was also a significant positive correlation between TAS and TOS. The activity of PON1 and ARE significantly increased only at diestrus. Levels of high density lipoprotein, low density lipoprotein and total cholesterol elevated during the follicular phase (estrus) and declined during the luteal phase. In conclusion, oxidant/antioxidant status and lipid profile were affected by cyclic changes. Moreover, antioxidant defense system showed adaptive response to increased oxidative activities by occurring parallel increases and it may indicate that there is a dynamic balance between oxidant and antioxidant status during the estrous cycle in healthy cows. Keywords: Cow, Estrous cycle, Lipid peroxide, Lipid profile, Total antioxidant status, Total oxidant status Sütçü İneklerde Östrus Siklusunun Oksidan ve Antioksidan Parametreler Üzerine Etkisi ÖzetReaktif oksijen türlerinin üreme fonksiyonları üzerinde önemli rolleri vardır. Sağlıklı süt sığırlarında reaktif oksijen türleri ve infertilite arasındaki ilişkiyi kapsamlı bir şekilde değerlendirmek için östrus siklusu boyunca reaktif oksijen türü seviyelerindeki değişimlerin bilinmesi gerekir. Bu çalışmada düzenli siklus gösteren 25 adet sağlıklı Holştayn ırkı sütçü inek kullanıldı. Östrus siklusları ovsynch protokolü ile senkronize edildi. Östrus siklusunun proöstrus, östrus, metaöstrus ve diöstrus dönemlerinde kan plazmasında oksidan parametreler [lipit hidroperoksit (LOOH), total oksidan seviye (TOS), oksidatif stres indeksi (OSI)], antioksidan parametreler [total antioksidan kapasite (TAS), total serbest sülfhidril gruplar (SH), seruloplazmin (CP), paraoksonaz-1 (PON1), arilesteraz (ARE), ürik asit (UA)], lipit profili ve progesteron seviyesi ölçüldü. Foliküler dönemle karşılaştırıldığında luteal dönemdeki plazma oksidan (LOOH, TOS, OSI) ve antioksidan (TAS, SH, UA) seviyelerinin önemli derecede düştüğü görüldü. Ayrıca TAS ve TOS değerleri arasında önemli bir pozitif korelasyon vardı. Paraoksonaz-1 ve ARE aktiviteleri sadece diöstrus ...

It is important to determine varying effects of anaesthetics agents. One of the adverse effects of general anaesthetics are the exogenous sources of reactive oxygen species. In this study, the effects of xylazine-tiletamine-zolazepam (XTZ) and fentanyl-tiletamine-zolazepam (FTZ) combinations on plasma oxidant-antioxidant indicators were compared in sheep. Ten ewes received two different anaesthetic combinations in a ten-day interval. XTZ group was injected with xylazine and tiletamine-zolazepam. FTZ group was injected with fentanyl and tiletamine-zolazepam. Blood samples were collected before and at the 30, 60, 120 min, 24 h and 3 days after anaesthesia. Both anaesthetic regimens caused an increase in malondialdehyde (MDA) concentrations in plasma. The MDA concentrations at 60, 120 min and 24 h in the XTZ group were significantly higher than in the FTZ group. Glutathione (GSH) concentration at 30, 60, 120 min and 24 h was significantly lower than baseline values in XTZ group, while there was only a decrease at 120 min in the FTZ group. GSH concentrations in the XTZ group were significantly lower at 60 and 120 min compared with the FTZ group. Beta carotene concentration was decreased at 120 min and 24 h in the XTZ group, while it decreased only at 120 min in the FTZ group. Glutathione peroxidase (GSH-Px) and catalase (CAT) activities decreased at 120 min and 24 h only in the XTZ group. There were no significant differences in -carotene concentration, activities CAT and GSH-Px activities between groups. In conclusion, both XTZ and FTZ anaesthetic regimens induced oxidative stress in sheep. XTZ combination has more detrimental effect than FTZ combinations on particularly MDA and GSH concentrations. Therefore, FTZ anaesthetic combination is considered to be more suitable for sheep anaesthesia, due to less deteriorating effects on oxidant/antioxidant balance. Anaesthesia, oxidative status, sheepGeneral anaesthesia is commonly used for surgical manipulations in small ruminants. An anaesthetic regimen with minimal side effects is desirable when anaesthesia is required for longer than 1 h in sheep (Lagutchik et al. 1991). One of the undesirable complications of general anaesthetics can be induced by reactive oxygen species (ROS) that occur during anaesthesia (Godin and Garnett 1994). Reactive oxygen species are produced as by-products of metabolism. In organisms, enzymatic (superoxide dismutase, catalase, glutathione peroxidase) and non-enzymatic (urate, cysteine, vitamin E, vitamin C, β-carotene) antioxidant defence systems maintain ROS concentrations in the physiological range. Oxidative stress occurs when the balance between ROS and antioxidants defence is disturbed. ROS cause cellular destruction by oxidative damage of DNA, proteins, lipids and carbohydrates, by changing the structure and function of key cellular constituents that result in mutation, cell damage and death (Simeonova et al. 2004). Thus, ROS play an important role in the pathogenesis of different diseases such as inflammation, carcinogenesis and isch...