Oxidant and antioxidant status of cadmium administered rats

Cadmium is one of the industrial elements that lead environmental pollution. Biological half-life of cadmium is relatively longer, so its clearance from tissue is considerably long. In present study, oxidant stress and antioxidant defense mechanism due to exposure to cadmium in rats wanted to be investigated. For such a purpose adult female wistar albino rats were divided into two as control and experimental groups. During experimental period while both group animals were fed by standard fodder, cadmium added (20 $\mu$g Cd/ml as cadmium sulfate) drinking water was given to experimental group for four weeks. At the end of four weeks blood samples were drawn from animals under ether anesthesia. As a Last product of lipid peroxidation malondialdehyde (MDA) level, superoxide dismutas (SOD) activity which is sign of antioxidant defense enzyme activity and glutathione levels (GSH) were measured. Increase in lipid peroxidation has been observed by increased MDA levels in experimental group (p$<$0.001). SOD enzyme activity was also found to be significantly lower in experimental group (p$<$0.001). Glutathione level of experimental group found to be decreased according to control group values (p$<$0.01). As a result of present study it may be concluded that cadmium may lead to increase in lipid peroxidation. On the other hand SOD activity and glutathione levels may also be decreased by effect of cadmium in erythrocytes. So the resultant would be the disturbed antioxidant mechanis

Erythrocyte osmotic fragility and oxidative stress in experimental hypothyroidism

The present study was planned to explain the relation between erythrocyte osmotic fragility and oxidative stress and antioxidant statue in primary hypothyroid-induced experimental rats. Twenty-four Spraque Dawley type female rats were divided into two, as control (n = 12) and experimental (n = 12), groups weighing between 160 and 200 g. The experimental group animals have received tap water methimazole added standard fodder to block the iodine pumps for 30 d (75 mg/100 g). Control group animals were fed tap water and only standard fodder for the same period. At the end of 30 d blood samples were drawn from the abdominal aorta of the rats under ether anesthesia. T-3, T-4, and TSH levels were measured and the animals that had relatively lower T-3, T-4, and higher TSH levels were accepted as hypothyroid group. Hormone levels of the control group were at euthyroid conditions. Osmotic fragility, as a lipid peroxidation indicator malondialdehyde (MDA), antioxidant defense system indicators superoxide dismutase (SOD) and glutathione (GSH) levels were measured in the blood samples. Osmotic fragility test results: There was no statistically significant difference found between maximum osmotic hemolysis limit values of both group. Minimum osmotic hemolysis limit value of hypothyroid group was found to be higher than that of control group values (p < 0.02). The standard hemolysis and hemolytic increment curve of the hypothyroid group drawn according to osmotic fragility test results was found to be shifted to the right when compared to control group's curve. This situation and hemolytic increment value, which shows maximum hemolysis ratio, is the proof of increased osmotic fragility of the erythrocytes in hypothyroidism. There is no statistically significant difference found between hypothyroid and control groups in the lipid peroxidation indicator MDA and antioxidant indicators SOD and GSH levels. As a result of our study it may be concluded that hypothyroidism may lead to an increase in osmotic fragility of erythrocytes. But the increase in erythrocyte osmotic fragility does not originate from lipid peroxidation

The effects of experimental hypothyroidism on hemorheology and plasma fibrinogen concentration

Effects of hypothyroid on hemorheology of patients had widely attracted the attention of researchers during last decade. The present study has been planned with the purpose to determine the effects of experimental hypothyroidism on hemorheological parameters and fibrinogen concentration. To induce experimental hypothyroid methimazole (75 mg/100 g) was added to the fodder of an experimental group rats for 20 d. After experimental duration, plasma and blood viscosity, hernatocrit (Hct), hemoglobin, erythrocyte rigidity index, and plasma fibrinogen concentration values of both the control and the experimental group animals were determined and evaluated. The serum T-3 and T-4 levels of the experimental group were found lower (p < 0.001) but TSH level higher (p < 0.001) than that of the control group. Plasma viscosity and fibrinogen concentration of hypothyroid group were found significantly higher than controls (p < 0.01). Hematocrit and hemoglobin values were also found lower in the experimental group than the control group animals (p < 0.01). However, there was no significant difference found in blood viscosity at the original Hct value but there was a significant increase at standard Hct value (p < 0.01). There was also no change in erythrocyte rigidity index between control and experimental groups. According to these results it may be said that in hypothyroidism, increased fibrinogen concentration may alter the rheological structure of blood by inducing increase in plasma viscosity

The effects of experimental hyperthyroidism on hemorheology and plasma fibrinogen concentration

The present study in female rats determined the effects of experimental hyperthyroidsm on hemorheological parameters and fibrinogen concentration. To induce experimental hyperthyroidism L-thyroxine (0.4 mg/100 g fodder) was added to the fodder of the experimental group rats for 20 d. After experimental duration, T-3, T-4, and TSH levels, plasma and blood viscosity, hematocrit, erythrocyte rigidity index, and plasma fibrinogen concentration values of both the control and the experimental group animals were determined and evaluated. In the experimental group, T-3 and T-4 levels were higher and TSH levels lower than that of the control rats (respectively,p < 0.011,p < 0.001,p < 0.001). Plasma viscosity and fibrinogen concentration of hyperthyroid group were found significantly higher than controls (p < 0.01). However there was no significant difference found in blood viscosity, hematocrit, and erythrocyte rigidity index between control and experimental groups. Thus, hyperthyroidism induced increased fibrinogen concentration can alter the rheological structure of blood by inducing increase in plasma viscosity

Investigation of tissue factor and other hemostatic profiles in experimental hypothyroidism

The influence of thyroid failure on hemostasis has been studied and is still not well understood. These patients have high risk for cardiovascular diseases because of the lipid metabolism and procoagulant agents. But the influence of thyroid failure on hemostasis is controversial. Tissue factor (TF) has an important role in the thromboembolic state. Recent experiments have demonstrated that TF-dependent activation of the coagulation cascade plays an important role in the pathophysiology of intravascular thrombus formation. The purpose of the present study was to investigate the contributions of TF, factor VII:C (FVII:C), factor XII:C (FXII:C), and fibrinogen in experimental hypothyroidism. TF was obtained from the thyroid gland and lung tissue of 10 rats following experimental hypothyroidism induced for 30 d and compared with similar tissue from 10 control rats. Significantly increased TF activities were found in hypothyroid rats. By contrast, FVII:C level was significantly decreased when compared with the control group. In this respect it is interesting to note that a hypercoagulable state due to increased thromboplastic activity may occur. Based on those results, elevated tissue factor activities (TFa) of the patients with low thyroid dysfunction may have another risk factor for cardiovascular diseases

Investigation of zinc and copper levels in methimazole-induced hypothyroidism: Relation with the oxidant-antioxidant status

Zn – zinc. Abstract. Thyroid hormones are associated with the oxidative and antioxidative status of the organism. Depression of metabolism by hypothyroidism has been reported to decrease oxidant production and thus protect tissues against oxidant damage. The purpose of the present study was to investigate Zn and Cu levels in MMI-induced hypothyroidism and to show whether there is a connection between these trace elements and the oxidant-antioxidant status in experimental hypothyroidism. 3-Nitrotyrosine was measured as a marker of nitro-oxidative stress. In or-der to examine the antioxidant status of MMI-induced hypothyroidism in rats, GSH and SOD levels were de-termined as well. Significantly decreased 3-nitrotyro-sine, Cu and Zn levels were observed in our experi-mental model when compared with the controls. On the other hand, GSH and SOD levels remained con-stant. It may be suggested that Cu and Zn serve as antioxidant molecules and exert their effects in an in-direct manner to reduce oxidative stress in experi-mental hypothyroidism