Gülin Güvendik

Effects of taurine on oxidative stress parameters and chromium levels altered by acute hexavalent chromium exposure in mice kidney tissue

The kidney has been regarded as a critical organ of toxicity induced by acute exposure to hexavalent chromium [Cr(VI)] compounds. Reactive intermediates and free radicals generated during reduction process might be responsible for Cr(VI) toxicity. In this study, the effects of pretreatment or posttreatment of taurine on Cr(VI)-induced oxidative stress and chromium accumulation in kidney tissue of Swiss albino mice were investigated. Single intraperitoneal (ip) potassium dichromate treatment (20 mgCr/kg), as Cr(VI) compound, significantly elevated the level of lipid peroxidation as compared with the control group (p<0.05). This was accompanied by significant decreases in nonprotein sulfhydryls (NPSH) level, superoxide dismutase (SOD), and catalase (CAT) enzyme activities as well as a significant chromium accumulation (p<0.05). Taurine administration (1 g/kg, ip) before or after Cr(VI) exposure resulted in reduction of lipid peroxidation levels and improvement in SOD enzyme activity (p<0.05). On the other hand, administration of the antioxidant before Cr(VI) exposure restored the NPSH level and CAT enzyme activity and also reduced tissue chromium levels (p<0.05), whereas postreatment had only slight effects on these parameters. In view of the results, taurine seems to exert some beneficial effects against Cr(VI)-induced oxidative stress and chromium accumulation in mice kidney tissue.

The determination of toxicities of sulphonylurea and phenylurea herbicides with quantitative structure-toxicity relationship (QSTR) studies.

Sulphonylurea and phenylurea herbicides are two groups of herbicides that are most commonly used worldwide. Quantitative structure-toxicity relationship models were derived for estimating the acute oral toxicity of these herbicides to male rats. The 20 chemicals of the training set and the seven compounds of external testing set were described by means of using descriptors for lipophilicity, polarity and molecular geometry, as well as the calculation of quantum chemical descriptors for energy. Model development to predict the toxicity of sulphonylurea and phenylurea herbicides in different matrices was carried out using multiple-linear regression. The model was validated internally and externally. In the present study, QSTR model was used for the first time to understand the inherent relationships between the sulphonyl and phenylurea-type herbicide molecules and their toxic behaviour. Such studies provide mechanistic insight about structure-toxicity relationships and assist in the design of less toxic herbicides.

Serum Selenium Levels in Cardiovascular Diseases : Kalp-Damar Hastalıklarında Serum Selenyum Düzeyleri

Redaksiyona verildigi tarih: 22.6.1993 *Department of Toxicology, Faculty of Pharmacy, Ankara University Ankara-TURKEY rollerle kiyaslanarak anlamli bir fark olup olmadiginin arastirilmasi amaclanmistir. Ortalama serum selenyum duzeyleri akut miyokard infarktuslu hastalarda 38.59 + 15.25 /L ( n = 2 2 ) , koroner arter hastalikli hastalarda 37.20 ± 11.44 / L (n=27) ve kontrol grubunda 63.66 + 11.71 / L (n = 21) olarak bulunmustur. Koroner arter hastaligi olan grupla, akut miyokard infarktuslu grup arasinda serum selenyum duzeylerinde onemli fark olmadigi halde (p>0.05), kontrol grubu ile her iki grup arasinda anlamli fark oldugu saptanmistir (p>0.01)