Selenium prevents lipid peroxidation in liver and lung tissues of rats in acute swimming exercise.

BACKGROUND: Selenium, which is critical for human health, is necessary for various metabolic processes, including thyroid hormone metabolism, protection against oxidative stress, and immune function. OBJECTIVE: The present study aims to examine how selenium administration affects lipid peroxidation in liver and lung tissues of rats subjected to acute swimming exercise. METHODS: The study included 32 Spraque-Dawley adult male rats divided into Group 1 (general control), Group 2 (selenium-administered), Group 3 (swimming), and Group 4 (selenium-administered swimming). MDA and GSH levels were determined in liver and lung tissues. RESULTS: The highest MDA values in the liver and lung tissues were found in group 3 in the study. MDA value in group 4 was higher than those in groups 1 and 2. Group 4 had the highest liver and lung GSH levels. GSH levels in Group 3 were higher than those in groups 1 and 2. CONCLUSION: Results of the study indicate that acute swimming exercise causes lipid peroxidation in liver and lung tissues, while selenium administration prevents free radical formation by increasing antioxidant activity (Tab. 2, Ref. 26).

Effect of boron supplementation on plasma element distribution in ovariectomized rats subjected to acute swimming exercise.

BACKGROUND: This study aims to examine how boron supplementation affects distribution of elements in the plasma of rats whose ovaries were removed and who were subjected to swimming exercise. METHODS: The study included 80 Sprague-Dawley type female rats, which were equally allocated to 8 groups. Group 1: General control, Group 2: Exercise control; Group 3: Ovariectomized control, Group 4: Ovariectomized exercise, Group 5: IP (intraperitoneal) boron-supplemented control, Group 6: IP boron-supplemented exercise, Group 7: Ovariectomized, IP boron-supplemented exercise, group 8: Ovariectomized, IP boron-supplemented. Following the exercise, blood samples were collected from all animals by decapitation, and analyzed in terms of plasma copper, iron, phosphorus, magnesium, calcium, and zinc using an atomic absorption spectrophotometer. RESULTS: Groups 1 and 5 had the lowest copper (p < 0.01) and the highest zinc and calcium (p < 0.01) levels, in comparison to other groups. Phosphorus levels in groups 3, 5 and 8 were significantly lower than those in other groups (p < 0.01). Magnesium levels in groups 3, 5 and 8 were higher, relative to the levels in other groups (p < 0.01). CONCLUSION: Results of the study indicate that acute swimming exercise in ovariectomized rats supplemented with boron leads to significant modifications in the distribution of some trace elements in the plasma. It can be emphasized as a separate result of this study that changes in copper, zinc and calcium levels were independent of boron supplementation (Tab. 2, Ref. 14).

Serum leptin and ghrelin concentrations of maternal serum, arterial and venous cord blood in healthy and preeclamptic pregnant women.

Preeclampsia, a common complication of pregnancy, is associated with alteration in the concentration of leptin in maternal blood. The action of leptin is antagonistic to that of ghrelin. Here, we compared the levels of leptin and ghrelin in maternal serum and in arterial and venous cord blood between healthy pregnant women and those suffering from mild and severe preeclampsia. The levels of leptin in maternal and newborn's blood were elevated in both mild and severe preeclamptic patients (p < 0.05). Moreover, serum ghrelin levels were negatively correlated with blood pressure and leptin/ghrelin ratio was decreased in preeclampsia (p < 0.05). We concluded that increased production of ghrelin may represent a compensatory hypotensive mechanism in preeclamptic women.

A comparison between the effects of low (1 microg) and standard dose (250 microg) ACTH stimulation tests on adrenal cortex functions with Behçet's disease.

INTRODUCTION: Behçet's disease is a rare, chronic disorder. The cause of Behçet's disease is unknown. It is believed to be caused by an autoimmune reaction. As in other chronic autoimmune diseases, Behçet's disease may show a subclinical adrenal failure and some changes in cortisol levels. We aimed to evaluate adrenal gland function in Behçet's disease patients. MATERIAL AND METHOD: This study included 18 Behçet's disease patients and 15 healthy controls. Patient and control groups were administered i.v. 1 microg low dose test (LDT) and 250 microg standard dose test (SDT) adrenocorticotropic hormone (ACTH) stimulation test after 12 h of night fasting with an interval of 3-days and cortisol responses in the 0th, 30th and 60th minutes were evaluated. RESULTS: There was no statistically significant difference between basal cortisol values of Behçet's disease and control groups. Cortisol values in the 60th minute in LDT were significantly lower in Behçet's disease group than in the control group. In the peak cortisol responses to LDT, a significant decrease was found in Behçet's disease group. CONCLUSION: These findings suggest that hypothalamo-pituitary adrenal axis is partially suppressed in Behçet's disease.

Plasma trace elements, vitamin B12, folate, and homocysteine levels in cirrhotic patients compared to healthy controls.

Increased serum homocysteine (Hcy) can induce liver diseases and can play a remarkable role in hepatic disorders. The purpose of the present study therefore was to investigate the relationship between serum vitamin B(12), folate, zinc and copper, cysteine, and Hcy level differences between cirrhotic patients and healthy subjects. We studied 32 cirrhotic patients (12 females and 20 males) aged 45 +/- 11 years and 32 control subjects (12 females and 20 males) aged 39 +/- 9 years. There was an inverse correlation between Hcy and vitamin B(12) in controls (r = -0.442, p < 0.011) but not in cirrhotic patients (r = -0.147, not significant). Also, mean plasma folate was decreased in cirrhotic patients compared to controls (p < 0.001). Copper increased whereas zinc decreased significantly in cirrhotic patients. A positive correlation was seen between the Cu/Zn ratio and Cu in controls (r = 0.690, p < 0.01), but the correlation between the Cu/Zn ratio and Cu was not significant in the cirrhotic group. Negative correlations were seen between plasma concentration of zinc and the Cu/Zn ratio in controls and cirrhotic patients (r = -0.618, p < 0.01 and r = -0.670, p < 0.01, respectively). Cirrhotic patients displayed multiple abnormalities, including changes in cysteine metabolism and in zinc and copper levels. Although hyperhomocysteinemia is known as an atherogenic and thrombogenic risk factor for cardiovascular disease, it might also be a risk factor for cirrhotic patients. Plasma Hcy, vitamin B(12), and folic acid measurement may be useful in the evaluation of cirrhotic patients.

Antioxidant status & lipid peroxidation in patients with rheumatoid arthritis.

BACKGROUND & OBJECTIVES: Rheumatoid arthritis (RA) is a debilitating, chronic multisystem disease with an unknown etiology. Recent findings indicate that increased oxidative stress and/or defective antioxidant status contribute to the etiology of RA. The present study was undertaken to examine the oxidant and antioxidant systems in patients with RA and healthy controls. METHODS: Twenty two patients with RA and 20 healthy volunteers were included in the study. Levels of malondialdehyde (MDA) and antioxidant vitamins (A, E, C) in serum samples were determined by high performance liquid chromatography (HPLC). Spectrophotometric methods were used to determine activity levels of antioxidant enzymes, superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px), in erythrocytes. RESULTS: MDA levels in patients with RA were found to be significantly (P<0.005) higher than controls whereas levels of vitamins A, E, C and activities of GSH-Px, SOD were lower in the patients compared to controls (P<0.005 for SOD and antioxidant vitamins; P<0.05 for GSH-Px). INTERPRETATION & CONCLUSION: There was an increased oxidative stress and a low antioxidant status in patients with RA. These changes are probably due to efforts for reducing lipid peroxidation and hence to lower tissue damage.

Tissue malondialdehyde and adenosine triphosphatase level after experimental liver ischaemia-reperfusion damage.

Functional irregularities due to damage after ischaemia-reperfusion vary depending upon the organs affected. High energy phosphates such as ATP and ADP are destroyed after ischaemia-reperfusion damage. Subsequently, protons and inorganic phosphates accumulate within the cells and the proton pumps such as adenosine triphosphatase (ATPase), which maintain intracellular ion balance are damaged. In the present study, malondialdehyde (MDA), a product of lipid peroxidation, was measured as an indicator of tissue damage. Additionally, we measured sodium-potassium-ATPase levels and determined the interactions between MDA and Na+-K+ ATPase levels. A total of 31 female guinea pigs were divided into four groups: sham operated guinea pigs (group 1), ischaemia-reperfusion (group 2), ischaemia-reperfusion + superoxide dismutase (SOD) (group 3), ischaemia-reperfusion + allopurinol (group 4). Following reperfusion, the livers of guinea pigs in each group were removed for histopathological examination and the levels of MDA and Na+-K+ ATPase were determined in homogenized tissue samples. There was a statistically significant (p < 0.05) reduction in tissue MDA levels in group 2 when compared with group 1. The level of tissue MDA in groups 3 and 4 was significantly lower than tissue MDA levels of group 2. However, there was a statistically significant (p < 0.05) reduction in tissue Na+-K+ ATPase levels of group 2 when compared with group 1. Similarly, the level of tissue Na+-K+ ATPase in groups 3 and 4 was significantly higher than the tissue Na+-K+ ATPase levels of group 2. The results of the histopathologic examination also revealed the beneficial effects of the use of SOD and allopurinol in preventing liver damage in cases of ischaemia-reperfusion. Although the levels of MDA and Na+-K+ ATP ase in group 2 were not equal to the level in group 1, antioxidant therapy significantly improved the tendency to reverse the effects of ischaemia-reperfusion and to protect the liver from damage due to ischaemia-reperfusion.

Protective effect of melatonin on antioxidative system in experimental ischemia-reperfusion of rat small intestine.

AIMS: Effect of exogenously administered melatonin (N-acetyl 5-methoxytryptamine) on antioxidant systems in experimental Ischemia-Reperfusion (I-R) of rat gastrointestinal system (GIS) was examined. METHODS: A total of 40 rats were divided into 4 groups: Group 1 (Sham), Group 2 (I-R), Group 3 (I-R + 10 mg/kg melatonin) and Group 4 (I-R + 20 mg/kg melatonin). Activity levels of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) were determined in small intestines. RESULTS: There was a significant (p<0.05) reduction in GSH-Px levels in Group 2 (64.16+/-7.02 U/mg protein) compared to Group 1 (80.15+/-9.32 U/mg protein). We observed a meaningful increase in GSH-Px levels in melatonin applied groups (Group 3: 75.94+/-9.83 U/mg protein, Group 4: 78.55+/-9.11 U/mg protein) compared to Group 2. Correspondingly, SOD activity levels were significantly reduced (p<0.001) in Group 2 (24.14+/-4.35 U/mg protein) compared to controls (52.91+/-6.13 U/mg protein). A stronger effect (p<0.001) of melatonin was observed on SOD levels compared to GSH-Px levels in both doses (Group 3: 38.96+/-6.39 U/mg protein, Group 4: 43.07+/-7.76 U/mg protein). Levels of selenium were reduced significantly in Group 2 (1.11+/-0.31 microg/g tissue) compared to Group 1 (2.01+/-0.19 microg/g tissue). Melatonin application in Group 3 (1.13+/-0.28 microg/g tissue) and Group 4 (1.89+/-0.48 microg/g tissue) caused an increase in selenium levels. There was a strong correlation between increases in selenium and GSH-Px levels in Group 4 (r:0.651 p<0.01). CONCLUSIONS: Melatonin seems to exert its antioxidant effect in GIS tract by stimulating SOD and GSH-Px. Selenium also seems to have an antioxidant contribution on protecting rat gastrointestinal tract I-R injury.

Angiotensin converting enzyme (ACE) activity levels in insulin-independent diabetes mellitus and effect of ACE levels on diabetic patients with nephropathy.

Involvement of complications is considered to be one of the major factors in the prognosis of diabetes mellitus (DM). Recent studies indicate that most diabetic complications such as nephropathy and hypertension are vascular-originated. Renin-angiotensin involvement, especially changes in ACE activity level, is considered to be a key factor since ACE converts angiotensin I to angiotensin II which is a potent vasoconstrictor and plays a vital role in the regulation of blood pressure. Our present study focused on ACE activity levels along with blood glucose and HbA(1c) levels in diabetic patients with (n=18) or without (n=25) nephropathy as compared to control subjects (n=25). Blood glucose levels were significantly higher in both diabetic groups compared to controls (p<0.001). On the other hand, compared to controls, blood HbA(1c) levels were slightly higher in DM patients without complications whereas they were significantly increased in nephropatic DM patients (p<0.001). There was a very strong increase (p<0.001) at the level of ACE activity in both of the diabetic groups (with nephropathy: 47.11+/-3.70 U l(-1); without complications: 43.72+/-2.93 U l(-1); controls: 25.15+/-2.30 U l(-1)). ACE activity levels were also significantly higher in diabetic patients with nephropathy than in type II DM patients without complication (p<0.01). Our results demonstrate that ACE activity levels are increased in diabetic patients. Additional significant increase in ACE activity levels in diabetic patients with complications such as nephropathy supports the hypothesis that ACE activity has an essential role in the development of complications in diabetes.

Effect of thinner inhalation on lipid peroxidation and some antioxidant enzymes of people working with paint thinner.

Paint thinner is a commonly used industrial solvent with considerable potential for abuse by inhalation. Paint thinner is taken into the body by inhalation or by contact with the skin. Paint thinner is oxidized gradually by cytochrome P450-dependent monooxygenase and consequently free radicals are produced. In the present study we measured plasma malondialdehyde (MDA, a product of lipid peroxidation) levels as an indicator of oxidative damage and activity levels of antioxidant enzymes gluthatione peroxidase (GSH-Px) and superoxide dismutase (SOD) in erythrocytes of a group of people (n = 18) working with paint thinner. The control group was composed of 18 healthy adults. There was a statistically significant (p < 0.001) increase in MDA (2.0+/-0.7 nmol ml(-1)) and GSH-Px (86.5+/-16.6 U g(-1) Hb) activity levels in people working with paint thinner compared with control subjects (MDA: 1.0+/-0.3 nmol ml(-1); GSH-Px: 53.9+/-14.5 U g(-1) Hb). Similarly, there was also an increase (p < 0.05) in the SOD levels (1079+/-214.6 U g(-1) Hb) of people working with paint thinner compared with controls (953.3+/-46.7 U g(-1) Hb). Based on our results, it can be concluded that paint thinner inhalation may increase lipid peroxidation and consequently induce antioxidant enzymes.