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Emre Sarandol - One of the best experts on this subject based on the ideXlab platform.
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high dose taurine supplementation increases serum paraoxonase and arylesterase activities in Experimental Hypothyroidism
Clinical and Experimental Pharmacology and Physiology, 2007Co-Authors: Melahat Dirican, Emre SarandolAbstract:SUMMARY 1 Hypothyroidism is accompanied by hyperlipidaemia and oxidative stress and is associated with several complications, such as atherosclerosis. Paraoxonase activity has been reported to decrease in several situations associated with atherosclerosis and oxidative stress. In the present study, the effects of different doses of taurine on serum paraoxonase and arylesterase activities, as well as on the serum lipid profile, were investigated in hypothyroid rats. 2 Forty male Sprague-Dawley rats were randomly divided into five groups as follows: Group 1, rats received normal rat chow and tap water; Group 2, rats received standard rat chow + 0.05% propylthiouracil (PTU) in the drinking water; and Groups 3–5, taurine-supplemented PTU groups (standard rat chow + 0.5, 2 or 3% taurine in the drinking water, respectively, in addition to PTU). Paraoxon or phenylacetate were used as substrates to measure paraoxonase and arylesterase activity, respectively. Plasma and tissue malondialdehyde (MDA) levels, indicators of lipid peroxidation, were determined using the thiobarbituric-acid reactive substances method. Serum triglyceride, total cholesterol and high-density lipoprotein–cholesterol (following precipitation with dextran sulphate–magnesium chloride) were determined using enzymatic methods. 3 Serum paraoxonase and arylesterase activities were increased and plasma and tissue MDA levels and serum triglyceride levels were reduced in a dose-dependent manner in taurine-treated hypothyroid rats. Taurine concentrations were positively correlated with enzyme activities and negatively correlated with MDA and triglyceride levels. 4 Further studies are needed to investigate the role of taurine supplementation in Hypothyroidism in human subjects.
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the effect of taurine supplementation on oxidative stress in Experimental Hypothyroidism
Cell Biochemistry and Function, 2006Co-Authors: Melahat Dirican, Emre Sarandol, Zehra SerdarAbstract:The purpose of this study was to investigate the oxidative status in Experimental Hypothyroidism and the antioxidant effect of taurine supplementation. Forty male Sprague Dawley rats were randomly divided into four groups (group 1, control; group 2, control + taurine; group 3, propylthiouracil (PTU); group 4, PTU + taurine). Hypothyroidism was induced by giving 0.05% PTU in drinking water for 8 weeks. Taurine was supplemented in drinking water at a concentration of 1% for 5 weeks. Plasma (p 0.05) malondialdehyde levels were increased in the PTU group compared with those of the control rats and were decreased in the PTU + taurine group compared with the PTU alone group. No significant changes were observed in glutathione levels of kidney and liver in the PTU group, but taurine supplementation significantly increased the glutathione levels of these tissues. Paraoxonase and arylesterase activities were decreased in the PTU group while taurine supplementation caused no significant changes in paraoxonase and arylesterase activities. These findings suggest that taurine supplementation may play a protective role against the increased oxidative stress resulting from Hypothyroidism. Copyright © 2004 John Wiley & Sons, Ltd.
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oxidative stress and serum paraoxonase activity in Experimental Hypothyroidism effect of vitamin e supplementation
Cell Biochemistry and Function, 2005Co-Authors: Emre Sarandol, Melahat Dirican, Zehra SerdarAbstract:Thyroid hormones are associated with the oxidative and antioxidative status of the organism. Since data on the oxidative status of Hypothyroidism are limited and controversial, we investigated the oxidant and antioxidant status and serum paraoxonase/arylesterase activities in propylthiouracil-induced Hypothyroidism and examined the effect of vitamin E supplementation on this Experimental model. Forty male Sprague Dawley rats were randomly divided into four groups (group 1, control; group 2, control+vitamin E; group 3, propylthiouracil; group 4, propylthiouracil+vitamin E). Plasma, red blood cell, liver, heart and skeletal muscle malondialdehyde levels were increased in the propylthiouracil-treated group compared with the control rats and were decreased in propylthiouracil+vitamin E group compared with the propylthiouracil-treated group. Vitamin E supplementation also significantly increased liver and kidney reduced glutathione levels in propylthiouracil treated animals. Serum paraoxonase and arylesterase activities were decreased in propylthiouracil treated group and vitamin E supplementation caused significant increase in serum paraoxonase activity compared with the propylthiouracil-treated rats. These findings suggest that Hypothyroidism is accompanied with increased oxidative stress and vitamin E supplementation exerts beneficial effects on this situation. Copyright © 2004 John Wiley & Sons, Ltd.
Melahat Dirican - One of the best experts on this subject based on the ideXlab platform.
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high dose taurine supplementation increases serum paraoxonase and arylesterase activities in Experimental Hypothyroidism
Clinical and Experimental Pharmacology and Physiology, 2007Co-Authors: Melahat Dirican, Emre SarandolAbstract:SUMMARY 1 Hypothyroidism is accompanied by hyperlipidaemia and oxidative stress and is associated with several complications, such as atherosclerosis. Paraoxonase activity has been reported to decrease in several situations associated with atherosclerosis and oxidative stress. In the present study, the effects of different doses of taurine on serum paraoxonase and arylesterase activities, as well as on the serum lipid profile, were investigated in hypothyroid rats. 2 Forty male Sprague-Dawley rats were randomly divided into five groups as follows: Group 1, rats received normal rat chow and tap water; Group 2, rats received standard rat chow + 0.05% propylthiouracil (PTU) in the drinking water; and Groups 3–5, taurine-supplemented PTU groups (standard rat chow + 0.5, 2 or 3% taurine in the drinking water, respectively, in addition to PTU). Paraoxon or phenylacetate were used as substrates to measure paraoxonase and arylesterase activity, respectively. Plasma and tissue malondialdehyde (MDA) levels, indicators of lipid peroxidation, were determined using the thiobarbituric-acid reactive substances method. Serum triglyceride, total cholesterol and high-density lipoprotein–cholesterol (following precipitation with dextran sulphate–magnesium chloride) were determined using enzymatic methods. 3 Serum paraoxonase and arylesterase activities were increased and plasma and tissue MDA levels and serum triglyceride levels were reduced in a dose-dependent manner in taurine-treated hypothyroid rats. Taurine concentrations were positively correlated with enzyme activities and negatively correlated with MDA and triglyceride levels. 4 Further studies are needed to investigate the role of taurine supplementation in Hypothyroidism in human subjects.
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the effect of taurine supplementation on oxidative stress in Experimental Hypothyroidism
Cell Biochemistry and Function, 2006Co-Authors: Melahat Dirican, Emre Sarandol, Zehra SerdarAbstract:The purpose of this study was to investigate the oxidative status in Experimental Hypothyroidism and the antioxidant effect of taurine supplementation. Forty male Sprague Dawley rats were randomly divided into four groups (group 1, control; group 2, control + taurine; group 3, propylthiouracil (PTU); group 4, PTU + taurine). Hypothyroidism was induced by giving 0.05% PTU in drinking water for 8 weeks. Taurine was supplemented in drinking water at a concentration of 1% for 5 weeks. Plasma (p 0.05) malondialdehyde levels were increased in the PTU group compared with those of the control rats and were decreased in the PTU + taurine group compared with the PTU alone group. No significant changes were observed in glutathione levels of kidney and liver in the PTU group, but taurine supplementation significantly increased the glutathione levels of these tissues. Paraoxonase and arylesterase activities were decreased in the PTU group while taurine supplementation caused no significant changes in paraoxonase and arylesterase activities. These findings suggest that taurine supplementation may play a protective role against the increased oxidative stress resulting from Hypothyroidism. Copyright © 2004 John Wiley & Sons, Ltd.
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oxidative stress and serum paraoxonase activity in Experimental Hypothyroidism effect of vitamin e supplementation
Cell Biochemistry and Function, 2005Co-Authors: Emre Sarandol, Melahat Dirican, Zehra SerdarAbstract:Thyroid hormones are associated with the oxidative and antioxidative status of the organism. Since data on the oxidative status of Hypothyroidism are limited and controversial, we investigated the oxidant and antioxidant status and serum paraoxonase/arylesterase activities in propylthiouracil-induced Hypothyroidism and examined the effect of vitamin E supplementation on this Experimental model. Forty male Sprague Dawley rats were randomly divided into four groups (group 1, control; group 2, control+vitamin E; group 3, propylthiouracil; group 4, propylthiouracil+vitamin E). Plasma, red blood cell, liver, heart and skeletal muscle malondialdehyde levels were increased in the propylthiouracil-treated group compared with the control rats and were decreased in propylthiouracil+vitamin E group compared with the propylthiouracil-treated group. Vitamin E supplementation also significantly increased liver and kidney reduced glutathione levels in propylthiouracil treated animals. Serum paraoxonase and arylesterase activities were decreased in propylthiouracil treated group and vitamin E supplementation caused significant increase in serum paraoxonase activity compared with the propylthiouracil-treated rats. These findings suggest that Hypothyroidism is accompanied with increased oxidative stress and vitamin E supplementation exerts beneficial effects on this situation. Copyright © 2004 John Wiley & Sons, Ltd.
Zehra Serdar - One of the best experts on this subject based on the ideXlab platform.
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the effect of taurine supplementation on oxidative stress in Experimental Hypothyroidism
Cell Biochemistry and Function, 2006Co-Authors: Melahat Dirican, Emre Sarandol, Zehra SerdarAbstract:The purpose of this study was to investigate the oxidative status in Experimental Hypothyroidism and the antioxidant effect of taurine supplementation. Forty male Sprague Dawley rats were randomly divided into four groups (group 1, control; group 2, control + taurine; group 3, propylthiouracil (PTU); group 4, PTU + taurine). Hypothyroidism was induced by giving 0.05% PTU in drinking water for 8 weeks. Taurine was supplemented in drinking water at a concentration of 1% for 5 weeks. Plasma (p 0.05) malondialdehyde levels were increased in the PTU group compared with those of the control rats and were decreased in the PTU + taurine group compared with the PTU alone group. No significant changes were observed in glutathione levels of kidney and liver in the PTU group, but taurine supplementation significantly increased the glutathione levels of these tissues. Paraoxonase and arylesterase activities were decreased in the PTU group while taurine supplementation caused no significant changes in paraoxonase and arylesterase activities. These findings suggest that taurine supplementation may play a protective role against the increased oxidative stress resulting from Hypothyroidism. Copyright © 2004 John Wiley & Sons, Ltd.
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oxidative stress and serum paraoxonase activity in Experimental Hypothyroidism effect of vitamin e supplementation
Cell Biochemistry and Function, 2005Co-Authors: Emre Sarandol, Melahat Dirican, Zehra SerdarAbstract:Thyroid hormones are associated with the oxidative and antioxidative status of the organism. Since data on the oxidative status of Hypothyroidism are limited and controversial, we investigated the oxidant and antioxidant status and serum paraoxonase/arylesterase activities in propylthiouracil-induced Hypothyroidism and examined the effect of vitamin E supplementation on this Experimental model. Forty male Sprague Dawley rats were randomly divided into four groups (group 1, control; group 2, control+vitamin E; group 3, propylthiouracil; group 4, propylthiouracil+vitamin E). Plasma, red blood cell, liver, heart and skeletal muscle malondialdehyde levels were increased in the propylthiouracil-treated group compared with the control rats and were decreased in propylthiouracil+vitamin E group compared with the propylthiouracil-treated group. Vitamin E supplementation also significantly increased liver and kidney reduced glutathione levels in propylthiouracil treated animals. Serum paraoxonase and arylesterase activities were decreased in propylthiouracil treated group and vitamin E supplementation caused significant increase in serum paraoxonase activity compared with the propylthiouracil-treated rats. These findings suggest that Hypothyroidism is accompanied with increased oxidative stress and vitamin E supplementation exerts beneficial effects on this situation. Copyright © 2004 John Wiley & Sons, Ltd.
Arshag D Mooradian - One of the best experts on this subject based on the ideXlab platform.
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malondialdehyde binding of rat cerebral proteins is reduced in Experimental Hypothyroidism
Brain Research, 1999Co-Authors: Joe Chehade, Jacob L Pinnas, Arshag D MooradianAbstract:To determine the effect of thyroid hormones (TH) on cerebral tissue malondialdehyde (MDA) content and accumulation of MDA-bound proteins, hyperthyroid rats and hypothyroid rats were compared to euthyroid controls. Hyperthyroidism was induced by daily injection of l-3,5,3′-triiodothyronine (15 ug (100 g)−1) intraperitoneally daily for 10 days. Hypothyroidism was induced with 0.025% methimazole in the drinking water for 4 weeks. Immunoblot analysis of cerebral and plasma proteins was carried out using a specific anti-MDA-protein antiserum. MDA was measured as thiobarbituric acid reactive substance. Hypothyroidism was associated with significant reduction in MDA-proteins of plasma (59.3±9.5% vs. 99.8±23.0% of control p<0.05) and cerebral tissue (17.6±19.9% vs. 100.2±29.0% of control p<0.001). Hyperthyroidism did not significantly alter MDA-protein distribution. These changes did not correlate with cerebral tissue or plasma MDA concentration. It is concluded that Hypothyroidism in rats is associated with significant decrease in MDA-bound proteins. This may have some clinical and biological implications.
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Malondialdehyde binding of rat cerebral proteins is reduced in Experimental Hypothyroidism.
Brain research, 1999Co-Authors: Joe Chehade, Jacob L Pinnas, Arshag D MooradianAbstract:To determine the effect of thyroid hormones (TH) on cerebral tissue malondialdehyde (MDA) content and accumulation of MDA-bound proteins, hyperthyroid rats and hypothyroid rats were compared to euthyroid controls. Hyperthyroidism was induced by daily injection of l-3,5, 3'-triiodothyronine (15 ug (100 g)-1) intraperitoneally daily for 10 days. Hypothyroidism was induced with 0.025% methimazole in the drinking water for 4 weeks. Immunoblot analysis of cerebral and plasma proteins was carried out using a specific anti-MDA-protein antiserum. MDA was measured as thiobarbituric acid reactive substance. Hypothyroidism was associated with significant reduction in MDA-proteins of plasma (59.3+/-9.5% vs. 99.8+/-23.0% of control p
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metabolic fuel and amino acid transport into the brain in Experimental Hypothyroidism
European Journal of Endocrinology, 1990Co-Authors: Arshag D MooradianAbstract:: The effect of Hypothyroidism in the adult rat on blood-brain barrier and muscle transport of hexoses, neutral amino acids, basic amino acids, monocarboxylic acids, and ketone bodies was examined using single arterial injection-tissue sampling technique. The cerebral blood flow and brain extraction of 3H2O (internal reference substance) was not altered in 3-month-old hypothyroid rats maintained on methimazole, 0.025% in the drinking water, for 7 weeks. The brain uptake index of D-beta-hydroxybutyrate was significantly reduced in hypothyroid rats (2.4 +/- 0.3 vs 4.6 +/- 0.6% p less than 0.001). Hypothyroid rats given thyroid hormone replacement therapy had normal brain uptake of D-beta-hydroxybutyrate (4.4 +/- 0.8%). The brain uptake index of butyrate was also significantly reduced in hypothyroid rats (39.3 +/- 2.1 vs 47.2 +/- 0.74%, p less than 0.001). The brain uptake index of other test substances and muscle uptake of nutrients examined were not altered in hypothyroid rats. These studies indicate that of the four transport systems examined in two tissues, the blood-brain barrier monocarboxylic acid transport system is most susceptible to the Hypothyroidism-induced changes.
Maria Luiza M Barretochaves - One of the best experts on this subject based on the ideXlab platform.
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cardiac angiotensin ii type i and type ii receptors are increased in rats submitted to Experimental Hypothyroidism
The Journal of Physiology, 2007Co-Authors: Marcela Sorelli Carneiroramos, Gabriela Placona Diniz, Jerusa Almeida, R Vieira, S V B Pinheiro, Robson A S Santos, Maria Luiza M BarretochavesAbstract:This study assessed the behaviour of angiotensin II (Ang II) receptors in an Experimental Hypothyroidism model in male Wistar rats. Animals were subjected to thyroidectomy and resting for 14 days. The alteration of cardiac mass was evaluated by total heart weight (HW), right ventricle weight (RVW), left ventricle weight (LVW), ratio of HW, RVW and LVW to body weight (BW) and atrial natriuretic factor (ANF) expression. Cardiac and plasma Ang II levels and serum T3 and T4 were determined. The mRNA and protein levels of Ang II receptors were investigated by RT-PCR and Western blotting, respectively. Functional analyses were performed using binding assays. T3 and T4 levels and the haemodynamic parameters confirmed the hypothyroid state. HW/BW, RVW/BW and LVW/BW ratios and the ANF expression were lower than those of control animals. No change was observed in cardiac or plasma Ang II levels. Both AT1/AT2 mRNA and protein levels were increased in the heart of hypothyroid animals due to a significant increase of these receptors in the RV. Experiments performed in cardiomyocytes showed a direct effect promoted by low thyroid hormone levels upon AT1 and AT2 receptors, discarding possible influence of haemodynamic parameters. Functional assays showed that both receptors are able to bind Ang II. Herein, we have identified, for the first time, a close and direct relation of elevated Ang II receptor levels in Hypothyroidism. Whether the increase in these receptors in Hypothyroidism is an alternative mechanism to compensate the atrophic state of heart or whether it may represent a potential means to the progression of heart failure remains unknown.
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cardiac at1 and at2 angiotensin ii receptors in Experimental Hypothyroidism
The FASEB Journal, 2006Co-Authors: Marcela Sorelli Carneiroramos, Gabriela Placonα Diniz, Maria Luiza M BarretochavesAbstract:Renin-angiotensin system (RAS) presents a close relation to thyroid hormone levels, but little is known about cardiac RAS in Hypothyroidism. We investigated the effect of Hypothyroidism on cardiac ...
