Esat Mahmut Kocaman

Deltamethrin attenuates antioxidant defense system and induces the expression of heat shock protein 70 in rainbow trout.

The current research aims to determine alterations in gene expression and enzymatic activity of fish antioxidant metabolism in response to pesticide administration. To this end, three different deltamethrin concentrations (0.25, 1, 2.5mug/L) were administrated to rainbow trout (Oncorhynchus mykiss) at different time intervals (6, 12, 24, 48 and 72h) in order to observe the influences of the pesticide on the activity of glutathione reductase, glucose 6-phosphate dehydrogenase, 6-ghosphogluconate dehydrogenase, and the expression of Hsp70 gene. We observed that the activities of the enzymes decreased with increasing deltamethrin concentrations and exposure time. The pesticide had more inhibitory effects on gill enzymes than those of muscle, liver and kidney. In addition, we detected that deltamethrin increased the expression of the stress-related protein Hsp70 with significant fold-chance values. The efficiency rate was 96.4% which is equal to 1.96 calculated via conversion formula used to calculate fold-chance value. We conclude that deltamethrin causes oxidative stress in fish both at protein and mRNA levels.

Effects of glyphosate on juvenile rainbow trout (Oncorhynchus mykiss): transcriptional and enzymatic analyses of antioxidant defence system, histopathological liver damage and swimming performance.

This study aims to determine the effect of glyphosate on the transcriptional and enzymatic activity of antioxidant metabolism enzymes of juvenile rainbow trout with short term (6, 12, 24, 48 and 96 h) and long term (21 days) exposures followed by a recovery treatment. This study also aims to determine the effects of glyphosate exposure on liver tissue damage and swimming performance due to short term (2.5, 5 and 10 mg/L) and long term (2.5 and 5 mg/L) exposures. Following pesticide administration, ten fish, each as a sample, were caught at 6th, 12th, 24th, 48th and 96th -h for the short term, and at 21st day for the long term exposure study. GPx activity was found to be significantly induced 12 h after the exposure to 2.5 mg/L of glyphosate as compared with the control group. A similar degree of induction was also observed for CAT activity but not for SOD. For long term exposure, except for the GPx activity after exposure to 5 mg/L of glyphosate, the activities of all other enzymes remained on a par with the control group. It was also observed that the levels of gene expression of these enzymes were not comparable with each other. It is assumed that these differences might result from the effect of glyphosate before translation and the possible reasons for this scenario are also discussed. The results of swimming performance are found to be consistent with responses of the antioxidant system, and they are attributed to the energy metabolism. The data are also supported with liver histopathology analysis.

Investigation of 8-OHdG, CYP1A, HSP70 and transcriptional analyses of antioxidant defence system in liver tissues of rainbow trout exposed to eprinomectin

&NA; Eprinomectin (EPM), a member of avermectin family, is a semi‐synthetic antibiotic. It has been known that avermectin family enters the aquatic environments and adversely affects the aquatic organisms. Effects of EPM is fully unknown in aquatic organisms especially fish, thus the aim of the present study was to investigate transcriptional changes (sod, cat, gpx) and activities of some antioxidant enzymes (superoxide dismutase (SOD), glutathione peroxidase (GPx) and catalase (CAT) and malondialdehyde (MDA) levels, oxidative DNA damage (8‐hydroxy‐2‐deoxyguanosine (8‐OHdG)) and transcriptional changes of heat shock protein 70 (HSP70), and cytochromes P4501A (CYP1A) in liver tissues of rainbow trout exposed to sublethal EPM concentration (0.001 &mgr;g/L, 0.002 &mgr;g/L, 0.01 &mgr;g/L, 0.05 &mgr;g/L) for 24 h, 48 h, 72 h and 96 h. The decrease in antioxidant enzyme (SOD, CAT and GPx) activity, transcriptional changes (sod, cat, gpx, HSP70 and CYP1A genes) and increase in MDA level and activity of 8‐OHdG in a dose–time‐dependent manner in the liver of rainbow trout were observed. The down‐regulated of antioxidant (sod, cat and gpx), HSP70 and CYP1A obviously, the severity of which increased with the concentration of EPM and exposure time. The results imply that EPM could induce oxidative damage to the liver tissue of rainbow trout. The information presented in this study is helpful to understand the mechanism of veterinary pharmaceuticals–induced oxidative stress in fishes. HighlightsEPM has biochemical and physiological effects in fish liver.These parameters may be involved in the toxicity mechanism of EPM on rainbow trout.8‐OHdG, CYP1A, HSP70 and antioxidant parameters might be utilized as a potential indicator of exposure to antibiotic in fish.

Assessment of 8-hydroxy-2-deoxyguanosine activity, gene expression and antioxidant enzyme activity on rainbow trout (Oncorhynchus mykiss) tissues exposed to biopesticide

The goal of this study was to determinate toxicity mechanism of biopesticide with antioxidant enzymes parameters such as superoxide dismutase (SOD), glutathione peroxidase (GPx) and catalase (CAT) and malondialdehyde (MDA) levels, oxidative DNA damage (8-hydroxy-2-deoxyguanosine (8-OHdG)), transcriptional changes of heat shock protein 70 (HSP70), and cytochromes P4501A (CYP1A), sod, cat, and gpx in liver and gill tissues of Oncorhynchus mykiss. For this aim, plant-based (natural pesticides, azadirachtin (AZA)) and synthetic pesticides (deltamethrin (DLM)) were exposed on the fish at different concentrations (0.0005 and 0.00025ppm of DLM; 0.24 and 0.12ppm of AZA) for 21 days. According to the results of the study, the activity of SOD, CAT and GPx decreased, but malondialdehyde (MDA) level and activity of 8-OHdG increased in the gill and liver of rainbow trout (p<0.05). Additionally sod, cat and gpx were down regulated; HSP70 and CYP1A were up regulated for transcriptional observation. The downwards regulation of antioxidant (sod, cat and gpx) and the upregulation of HSP70 and CYP1A was obvious with doses of AZA or DLM (p<0.05). The findings of this study suggest that biopesticide can cause biochemical and physiological effects in the fish gill and liver by causing enzyme inhibition, an increase in 8-OHdG levels and changes in both transcriptional parameters (sod, cat, gpx, HSP70 and CYP1A). We found that excessive doses of plant-based pesticide are nearly as toxic as chemical ones for aquatic organisms. Moreover, 8-OHdG, HSP70 and CYP1A used as a biomarker to determinate toxicity mechanism of biopesticide in aquatic environment.

Growth of Trout Juveniles (Oncorhynchus mykiss, Salvelinus fontinalis and Salmo trutta fario) under Uniform Cultural Conditions

Abstract Kocaman, E.M., Bayir, A., Sirkecioğlu, A.N., Cengiz Bayir, M. and Yanik, T. 2006. Growth of trout juveniles (Oncorhynchus mykiss, Salvelinus fontinalis and Salmo trutta fario) under uniform cultural conditions. J. Appl. Anim. Res., 30: 73–75. Growth of trout juveniles namely rainbow trout (Oncorhynchus mykiss), brown trout (Salmo trutta faria) and brook trout (Salvelinus fontinalis) were determined under same environmental conditions. Although the initial average weights of the three trouts were similar, the average final weights, rate of weight gain and feed per unit gain were superior in rainbow and brook trouts as compared to brown trout. Survival rate during the 140 d experimental period was 100% in all species. Thus faster and economic growth of rainbow trout over other cultured trouts is demonstrated.

Gökkuşağı Alabalığı’na (Oncorhynchus mykiss) Uygulanan Formaldehit Banyosunun Bazı Hematolojik Kan Parametreleri Üzerine Etkisi

Bu arastirmada, balik hastaliklarinin tedavisinde yaygin bir sekilde kullanilan formaldehit’in Gokkusagi alabaligi ( Oncorhynchus mykiss )’nin bazi hematolojik parametreleri uzerine etkisi arastirilmistir. Arastirmadan elde edilen sonuclara gore , dozxsure interaksiyonunda olculen hematokrit degerleri arasindaki farklilik istatistiksel olarak onemli (p<0,05) bulunmustur. Hemoglobin miktarinda uygulama dozu ve dozxsure interaksiyonunun istatistiksel anlamda cok onemli (p<0,01), uygulama suresinin ise onemli (p<0,05) oldugu saptanmistir. Retikulosit orani bakimindan uygulama dozu ile uygulama suresi istatistiksel olarak cok onemli (p<0,01) oldugu gorulmustur.

Effects of iron chloride/zeolıte on G6PD of rainbow trout (Oncorhynchus mykiss)’s liver tissue

Aquatic ecosystems have been negatively affected by the contamination of ground and surface waters as a result of various activities. Due to the ferrous chloride (FeCl2), which is used as the reducing agent for the organic synthesis reactions in the contamination of water column and sediment, iron salts may be very toxic for some aquatic organisms. In order to minimize these effects, natural products such as zeolite have been widely used in recently years.For this reason, rainbow trout were exposed to FeCl2 and/or zeolite ((FeCl2 (0.002 mg/l)(A), FeCl2+zeolite (0.002 mg/l+1 gr/l) (B), zeolite (1 gr/l) (C) and control (without FeCl2 and/or zeolite (D)). for 28 days and their oxidative stress responses were investigated. At the end of the treatment period, Glucose-6- phosphate dehydrogenase (G6PD) activity was determined in the samples taken from livers. G6PD values for liver tissues were found statistically important in the control and treatment groups (p<0.01).