Browsing by Author "Türkoglu, V"

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Effects of Propylthiouracil-Induced Hypothyroidism on Plasma Lipid Table in Rabbits
(Tubitak Scientific & Technological Research Council Turkey, 2000) Çelik, I; Türkoglu, V; Yegin, E
Hypothyroidism is commonly associated with hyperlipidemia. The aim of this study was to investigate the effect of Propylthiouracil-induced hypothyroidism on the plasma lipid profile in rabbits. This investigation was performed on male, white New Zealand (Oryctolagus cuniculus huxley) rabbits, Twenty rabbits were used; each of the two groups (hypothyroidism and control) consisted of ten animals, Hypothyroidism was induced by oral administration of Propylthiouracil 50 mg.kg(-1) for three weeks. The mean values of Triiodothyronine (T-3), thyroxine (T-4), free T-3 (FT3) and free T-4 (FT4) were 121.7+/-32.7 ng/dl, 1.81+/-0.60 mu g/dl, 2.36+/-9b92 ng/dl and 0.43+/-0.22 p mol/dl in the control group, and 88.4+/-19.2 ng/dl, 1.15+/-0.37 mu g/dl, 1.48+/-0.44 ng/dl and 0.18+/-0.11p mol/dl in the hypothyroidism group, respectively (p<0.05 for all). Levels of total plasma triglyseride (TG), high-density lipoprotein cholesterol (HDL-C), total cholesterol (TC) and apolipoprotein-B (Apo-B) were recorded as 44.2+/-8.57, 12.2+/-2.7, 40.4+/-14.9 and 87.2+/-19.2 mg.dl(-1) in the control group, and 97.9+/-29.8. 23.2+/-2.9, 67.2+/-13.5 and 147.4+/-55.7 mg.dl(-1) in the hypothyroidism group, respectively (p<0.001 for all parameters). The results showed that T-3, T-4, FT3 and FT4 decreased in the hypothyroidism group, but lipid fractions were higher than in the control group. In addition, a significant negative correlation was found between T-4-TC (r=-0.739, p<0.05) and T-4-Apo-B (r=-0.666, p<0.05).
Purification and Characterization of Acetylcholinesterase From Sheep Liver and Inhibition by Some Painkillers
(Asian Journal of Chemistry, 2006) Güloglu, OF; Türkoglu, V; Çelik, I
In this study, acetylcholinesterase (AChE; EC 3.1.1.7) was purified from sheep liver by affinity chromatography. The purification rate was found 3541.7 fold. The purification control of enzyme was done with sodium dodesilsulfate-polyacrylamide gel electrophoresis (SDS-PAGE). The optimal pH, ionic strength and temperature of enzyme were determined. The optimal pH and the optimum temperature were 7.5-8.5 and 35 degrees C respectively. The highest activity was seen in concentration of 0.2 M (NH4)(2)SO4 as ionic strength. On the other hand, the inhibition effects of some painkiller, (paracetamol + caffein), (neostigmin methylsulfate) and (paracetamol + propifenazon + caffein) were investigated in this study. According to results, the I-50 values are 1.27 X 10(-3), 1.02 x 10(-4) and 1.236 M respectively. Also, K-i values are determined as 1.246 x 10(-3), 4.326 x 10(-5) and 1.646 x 10(-3) mol(-1) min(-1) respectively.
Purification and Characterization of Glucose 6-Phosphate Dehydrogenase From Sheep Liver
(Tubitak Scientific & Technological Research Council Turkey, 2003) Türkoglu, V; Aldemir, S; Çiftçi, M
Glucose 6-phosphate dehydrogenase (D-glucose 6-phosphate: NADP(+) oxidoreductase, EC 1.1.1.49; G6PD) was purified from sheep liver by a simple and rapid method. The purification process consisted of two steps: preparation of the homogenate, and 2, 5'-adenosine diphosphate (ADP) Sepharose 4B affinity chromatography. Through the use of these two consecutive steps, the enzyme was purified with a yield of 35.6% and 1,920 fold, having the specific activity of 11.2 enzyme units (EU/mg protein). A K-M of 0.176 mM and a V-max of 0.0179 EU/ml were obtained for G6-P, and 0.0194 mM and 0.0223 EU/ml for NADP(+). Enzymatic activity was measured spectrophotometrically according to Beutler's method at 340 nm and optimal pH and assay temperature were determined. By means of a Lineweaver-Burk plot, the inhibitor constant for NADPH was determined to be K-i, 4.707 +/- 0.49 muM and it was shown to inhibit the enzyme in a non-competitive manner. The purification of enzyme was monitored by sodium dodecyl sulfate (SDS) polyacrylamide gel electrophoresis (SDS-PAGE). SDS-PAGE showed a single band at similar to55 kDa for the enzyme and gel filtration chromatography indicated it to be a dimer.