The effects of n-3 long-chain polyunsaturated fatty acid supplementation on AGEs and sRAGE in type 2 diabetes mellitus

In diabetes mellitus, chronic hyperglycemia leads to formation of advanced glycation end products (AGEs). Binding of AGEs to receptors of AGE (RAGE) causes deleterious effects. In populations with a high consumption of n-3 long-chain polyunsaturated fatty acids, a lower prevalence of diabetes mellitus has been reported. We aimed to investigate the effects of n-3 fatty acid (EPA and DHA) supplementation on the levels of AGEs (carboxymethyl lysine (CML) and pentosidine), sRAGE, and nuclear factor kappa B (NF-kB) in type 2 diabetes mellitus (T2DM). T2DM patients (n = 38) treated with oral hypoglycemic agents, without insulin were supplemented with n-3 fatty acids (1.2 g/day) for 2 months. Plasma CML, pentosidine, sRAGE, and NF-kB levels were measured by ELISA both before and after the supplementation. n-3 fatty acid supplementation significantly reduced fasting glucose (p < 0.01), glycated hemoglobin (HbA_1c) (p < 0.05), and pentosidine (p < 0.05) levels. The supplementation induced percentage changes in pentosidine and HbA_1c and in pentosidine and creatinine were observed to be correlated (r = 0.349, p < 0.05) and (r = 0.377, p < 0.05), respectively. Waist circumference and systolic and diastolic pressures were significantly decreased due to n-3 supplementation (p < 0.001, p < 0.01, p < 0.01), respectively. Our results show that supplementation with n-3 fatty acid has beneficial effects on waist circumference; systolic and diastolic blood pressures; and the levels of glucose, HbA_1c, and pentosidine in T2DM patients. However, the supplementation failed to decrease these parameters to the reference ranges for healthy subjects. In addition, the supplementation did not appear to induce any significant differences in CML, sRAGE, or NF-kB.

Soluble Lectin-Like Oxidized LDL Receptor 1 as a Possible Mediator of Endothelial Dysfunction in Patients With Metabolic Syndrome

BACKGROUND

Metabolic syndrome (MetS) defines a well-known cluster of metabolic disturbances associated with an increased risk of cardiovascular disease and diabetes. The aim of this study was to examine the distribution of soluble lectin-like oxidized low-density lipoprotein (LDL) receptor-1 (sLOX-1) levels in patients with MetS, possible association of sLOX-1 with oxidized LDL (oxLDL), endothelial nitric oxide synthase (eNOS), nitric oxide (NOx), endothelin-1 (ET-1), paraoxonase 1 (PON1), and arylesterase (ARE) activities, and these parameters compared with healthy controls.

METHODS

A total of 55 patients (37 women, 18 men) with MetS and 29 healthy controls (19 women, 10 men) with a body mass index (BMI) less than 25 kg/m(2) were enrolled in the study.

RESULTS

sLOX-1, oxLDL, and ET-1 levels were significantly higher in patients with MetS than in control subjects (P = 0.023 P < 0.001, and P < 0.001, respectively). MetS patients have significantly lower eNOS and NOx levels, and PON1 and ARE activities than control subjects (P = 0.017, P < 0.004, P < 0.001, and P = 0.010, respectively). A positive correlation was observed between the sLOX-1 levels and the oxLDL, ET-1, BMI, glucose levels. ET-1 levels also exhibited significant negative correlation with ARE activity.

CONCLUSION

sLOX-1 levels are associated with cardiovascular risk factors, such as increased oxLDL, obesity, and diabetes, in patients with MetS. An increased concentration of sLOX-1 could be an early predictor of endothelial damage in MetS. In addition, it appears that oxLDL, ET-1, eNOS, NOx, PON1, and ARE activities may accurately reflect the levels of endothelial dysfunction in MetS patients.

Relation of protein oxidation parameters and disease activity in patients with Behçet's disease

BACKGROUND

Behçet's disease (BD) is a chronic inflammatory vasculitis characterized by endothelial dysfunction, elevated reactive oxygen species (ROS), and neutrophil hyperfunction production including acute attacks and remission periods. Ischemia modified albumin (IMA), advanced oxidation protein products (AOPP), prooxidants-antioxidants balance (PAB), and ferric reducing antioxidant power (FRAP) were evaluated in regard to their role in the pathogenesis of BD as well as their relation to clinical presentation, uveitis attacks and remission periods, and healthy volunteers.

METHODS

The study included 28 BD cases and 27 healthy volunteers as the control group. Blood samples were taken twice from each patient; first during an attack and second about three months after an attack, during remission period.

RESULTS

AOPP, IMA and PAB levels were significantly increased in active periods of patients with BD compared with healthy control and remission periods of patients with BD (p < 0.0001, p < 0.0001, p < 0.0001, respectively). FRABP levels were found to be lower in active periods of patients with than healthy controls and remission periods of patients with BD (p < 0.001, p < 0.05, respectively). The AOPP levels were negatively correlated with the levels of FRAB in patients (r = -0.468, p = 0.012; r = -0.394, p = 0.038, respectively). The PAB levels were positively correlated with the levels of CRP in patients (r = -0.606, p = 0.001).

CONCLUSIONS

Our results show that these parameters play a major role in the inflammatory reactions observed in BD. Increased levels of IMA and PAB are likely to be a result of inflammation-induced oxidative stress and hence its potential significance as a new marker of oxidative stress in BD.

Effects of omega-3 polyunsaturated fatty acid supplementation on serum fetuin-A levels in type 2 diabetic patients

Fetuin-A is an endogenous inhibitor of the insulin-stimulated insulin receptor tyrosine kinase recently shown that high levels of circulating fetuin-A are associated with insulin resistance in humans suggesting that fetuin-A may represent a novel mechanism involved in the pathophysiology of type 2 diabetes (T2DM). Dietary omega-3 polyunsaturated fatty acids (n-3 PUFAs) are known to reduce triglyceride levels, but their impact on glycemic control are not well known. The aim of this study to determine the effects of omega-3 PUFA supplementation on fetuin-A and glycemic control in patients with type 2 diabetes mellitus. 40 T2DM patients (17 males/23 females; aged 39-65 years) were included in the study. Serum fetuin-A levels and metabolic and biochemical profiles were measured before (baseline) and two months after n-3 PUFA supplementations (1.2 g/day). Serum fetuin-A levels were measured by enzyme-linked immunosorbent assay. Our results indicated that serum fetuin-A, fasting glucose, HbA1c and triglyceride levels were significantly decreased after supplementation (P<0.02, P<0.001, P<0.02 and P<0.01, respectively). At baseline, serum fetuin-A levels were correlated with HbA1c (r:-0.391, P<0.04). A significant positive correlation between fetuin-A and both triglycerides (r: 0.343, P<0.05) and total cholesterol (r: 0.330, P<0.05) and negative correlation between fetuin-A and fasting glucose (r: -0.405, P<0.01) were found after the supplementations. When performed multiply regression analysis, we found that serum fetuin-a levels were related with triglyceride levels (r: 0.351, P<0.01) at baseline and HbA1c levels (r: 0.344, P<0.04) after the supplementation. Based on the results, it thought that omega-3 PUFA intake decreases serum fetuin-A levels and serum fetuin-A is associated with plasma lipids and glycemic controls in type 2 diabetic patients. Further studies are required to resolve the question.

Plasma AGE-peptides and C-peptide in early-stage diabetic nephropathy patients on thiamine and pyridoxine therapy

AIM

The aim of the study was to evaluate circulatory AGE-peptide levels in diabetic nephropathy and to observe the effects of thiamine (vitamin B1) and pyridoxine (vitamin B6) therapy.

METHODS

Type 2 diabetic patients (N.=57) were divided into two groups as "with nephropathy" (N.=27) and "without nephropathy" (N.=30). Diabetic nephropathy patients were treated with either B6 (N.=12) (250 mg/day) or B1+B6 (N.=15) (250 mg/day, each) for five months. At the beginning and the end of the experimentation period, glucose, HbA1c, triglyceride, cholesterol, insulin, C-peptide, thiamine pyrophosphate, pyridoxal phosphate and AGE- peptides were measured.

RESULTS

AGE-peptides were higher in the diabetic group with nephropathy than without nephropathy (P=0.005). Within five months AGE-peptides increased in the diabetic group without nephropathy (P=0.042) but not in the group with nephropathy treated either with B1+B6 or B6. In B6 treated group a substantial decrease was observed in HbA1c (P=0.033). B1+B6 or B6 treatment both caused an increase in C-peptide (P=0.006, P=0.004).

CONCLUSION

Among the parameters measured, plasma AGE-peptides was the only parameter found to be higher in type 2 diabetes mellitus patients "with nephropathy" than "without nephropathy". However, patients with nephropathy treated with B1+B6 or B6 did not display any further increase in AGE-peptides within five months. Both of the treatments caused an increase in C-peptide.

Serum brain-derived neurotrophic factor, nerve growth factor and neurotrophin-3 levels in dementia

The aim of this study is to measure serum levels of neurotropic factor (NF) in patients with dementia. Brain-derived neurotrophic factor (BDNF), nerve growth factor (NGF), and neurotrophin-3 (NT-3) were determined in Alzheimer's dementia patients without medication (AD; n: 22), Alzheimer's dementia patients receiving cholinesterase inhibitor (CEI) treatment (AD + CEI; n: 32) and vascular dementia patients receiving CEI treatment (VaD + CEI; n: 27) and the age-matched control group (n: 20). NGF levels were detected to be significantly higher in the control group than in AD group (P < 0.001). BDNF and NT-3 levels in AD group were not significantly different from control group's levels. NGF levels in AD + CEI group were significantly higher than in AD group (P < 0.05). There was also no significant difference in serum neurotrophic factor levels between AD + CEI and VaD + CEI group. A positive correlation between BDNF and Mini Mental State Examination (MMSE) scores (r: 0.422, P < 0.01) in AD group and a negative correlation between BDNF and MMSE scores in the AD + CEI group (r: -0.357, P < 0.005) were obtained. In conclusion, our results suggest that while serum NGF levels are associated with the presence of dementia, serum BDNF levels may be associated with the severity of Alzheimer's dementia. However, future studies are required to determine the importance of NFs.

Plasma oxidative and inflammatory markers in patients with idiopathic Parkinson's disease

Parkinson's disease (PD) is the most common neurodegenerative disorder after alzheimer's disease. Neuroinflammation and oxidative damage are implicated to be responsible for the pathogenesis of neurodegenerative diseases. However, there are a few studies showing the changes in the biomarkers for neuroinflammation and oxidative damage in neurodegenerative diseases. In our study we aimed to examine the role of the molecules that are involved in oxidative stress and inflammation in PD patients taking L: -dopa treatment. Oxidized-LDL (ox-LDL), high-sensitivity C-reactive protein (hs-CRP) and the soluble intracellular adhesion molecule (ICAM) were chosen as biomarkers for systemic inflammation and oxidative damage. The patients were classified according to the Hoehn-Yahr staging system. Forty-five idiopathic L: -dopa-given PD patients and 25 age-matched healthy controls were examined. Plasma ox-LDL and ICAM levels were significantly higher in PD patients when compared with controls (p < 0.001 and p < 0.05, respectively). PD patients at all stages had significantly higher plasma ox-LDL levels than controls (p < 0.001). Plasma ICAM levels at stage 1 and 2 and CRP levels at stage 2 patients were significantly higher than controls (p < 0.05, p < 0.05, and p < 0.01, respectively). We insist that further studies have to be conducted to establish neuroinflammation and oxidative damage in PD. Establishing the roles of these pathological processes in PD might be the key to effective therapy at an early stage by antioxidants and/or anti-inflammatory drugs.

Increased testicular 8-hydroxy-2'-deoxyguanosine (8-OHdG) and inducible nitric oxide synthetase (iNOS) and nuclear factor κB (NF-κB) expressions in experimental rat varicocele

OBJECTIVES

To assess nuclear factor-kappaB (NF-kappaB), inducible NO synthase (iNOS) immunohistochemically, and 8-hydroxy-2'-deoxyguanosine (8-OHdG) biochemically, which are sensitive biological markers of oxidative damage and stress, in testes with experimental varicocele.

MATERIALS AND METHODS

Adult rats were randomly divided into three groups. Control group (n: 10), sham group (n: 10), varicocele group (n: 10). Of 14 rats undergoing partial ligation of the left renal vein, 10 rats had developed dilation of the left spermatic vein when evaluated 3 months after varicocele-inducing surgery. The rats were sacrificed after 3 months of the varicocele-inducing surgery. Ipsilateral and contralateral testes were examined for 8-hydroxy-2'-deoxyguanosine (8-OHdG) biochemically, inducible NO synthase (iNOS) and nuclear factor-kappaB (NF-kappaB) expression immunohistochemically.

RESULTS

Inducible NO synthase (iNOS), nuclear factor-kappaB (NF-kappaB) expressions and 8-hydroxy-2'-deoxyguanosine (8-OHdG) levels in both testes of varicocele group were markedly higher compared with control and sham groups (p < 0.01). There was no difference between control and sham groups (p > 0.05).

CONCLUSIONS

Regarding to our results, we suggest that varicocele may produce oxidative stress in both of testes, and we believe that this stress may play a role in male fertility.

Oxidized LDL and anti-oxLDL antibody levels in peripheral atherosclerotic disease

OBJECTIVE

Oxidative modification of LDL (oxLDL) is important in atherogenesis and is proposed as a useful marker for identifying patients with coronary artery disease. Antibody to oxLDL (oxLDL Ab) is detected in human sera, although its biological significance is not well established. We aimed to measure oxLDL and oxLDL Ab in peripheral atherosclerotic disease (PAD) patients, and to examine the relation between them in an attempt to understand the role of oxLDL Ab. Total risk of atherosclerosis was estimated using the global risk assessment score (GRAS) calculated on the basis of age, total cholesterol, HDL cholesterol (HDL-Chol), diabetes, hypertension and smoking.

MATERIAL AND METHODS

Twenty-one patients aged 63.05+/-9.13 years, diagnosed by peripheric angiography as PAD, and 21 healthy controls aged 47.67+/-13.61 years took part in the study. Total LDL and HDL cholesterol levels were determined by enzymatic methods. Levels of circulating oxLDL were measured by monoclonal antibody 4E6-based competition ELISA. IgG class oxLDL Ab titre was measured by ELISA.

RESULTS

Compared to healthy controls, PAD patients had higher levels of oxLDL (p<0.05), oxLDL Ab (p<0.05), LDL cholesterol (LDL-Chol) (p<0.05), total cholesterol (p<0.05) and lower HDL-Chol (p<0.05). OxLDL was found to be positively correlated with total cholesterol (r = 0.471, p<0.05) and LDL-Chol (r = 0.614, p<0.01) and GRAS (r = 0.435, p<0.05) and negatively with HDL-Chol (r = -0.459, p<0.05), but not with oxLDL Ab in PAD patients.

CONCLUSIONS

These findings might indicate that high LDL-Chol levels influence the oxidation of LDL and that oxLDL is a possible marker of PAD. However, the role of oxLDL Ab in atherosclerosis remains controversial.

Homocysteine and nitric oxide in patients undergoing diagnostic coronary angiography

We evaluated the plasma homocysteine (tHcy) and nitric oxide metabolites (nitrite plus nitrate; NOx) data of consecutive patients undergoing diagnostic coronary angiography (n=79) with respect to the presence and severity of coronary artery disease (CAD), the presence of acute coronary syndromes (ACS), and the risk status of patients. Hyperhomocysteinemia (>15 micromol/L) was detected in 11% of the controls (n=19) and 37% of CAD patients (n=60) (p=0.03). Plasma tHcy in CAD patients was not significantly different from controls, but those with 3-vessel disease had a significantly higher tHcy concentrations than did controls (p=0.049). The patients with 3-vessel disease and ACS had the highest concentrations of tHcy (16.9 +- 4.4 micromol/L), and the difference from the ACS patients with 1- and 2-vessel involvement was significant (p=0.03). In patients with 1-vessel involvement, tHcy was correlated with NOx (r=0.62, p=0.005); in patients with 2- and 3-vessel disease this correlation could not be observed. The high-risk patients (n=51) had a higher mean number of vessel involvement and tHcy (p<0.001, p<0.05, respectively) but lower NOx (p<0.05) when compared to the low-risk patients (n=28). It appears that in the early stages of atherosclerosis hyperhomocysteinemia causes an increase in NOx production, but with progression of the disease this compensatory increase disappears.

Oxidative damage to nuclear DNA in streptozotocin-diabetic rat liver

1. Accumulating evidence suggests that oxidative and glycative stress is enhanced in diabetes. Oxidative stress induces DNA damage. In the present study, we assessed the 8-oxo-2'-deoxyguanosine (8-oxodG) content of DNA, an indicator of oxidative DNA damage, in streptozotocin (STZ)-induced diabetic (n = 21) and control rats (n = 18). 2. Rats were rendered diabetic by intraperitoneal administration of STZ at a dose of 65 mg/kg. Glucose was determined by glucose oxidase and glycated haemoglobin (GHb), an indicator of glycative stress, was determined by agarose-boronate affinity chromatography. 8-Oxo-2'-deoxyguanosine within the DNA (ratio of 8-oxodG to deoxyguanosine (dG)) was assessed by HPLC in conjunction with both electrochemical (8-oxodG) and diode array (dG) detection. 3. Glucose, GHb and the extent of oxidative DNA damage in the liver of STZ-diabetic rats were much higher compared with control rats. There was a correlation between GHb and 8-oxodG/10(5) dG levels in control (r = 0.756, P < 0.001) and diabetic groups (r = 0.468, 0.02 < P < 0.05). 4. These results clearly show that oxidative damage to hepatic nuclear DNA increases in the diabetic state and that this increase is correlated with glycative stress.

Oxidative stress and nitric oxide in rats with alcohol-induced acute pancreatitis

AIM: Oxygen free radical mediated tissue damage is well established in pathogenesis of acute pancreatitis (AP). Whether nitric oxide (NO) plays a deleterious or a protective role is unknown. In alcohol-induced AP, we studied NO, lipooxidative damage and glutathione in pancreas, lung and circulation.

METHODS: AP was induced in rats (n = 25) by injection of ethyl alcohol into the common biliary duct. A sham laparatomy was performed in controls (n = 15). After 24 h the animals were killed, blood and tissue sampling were done.

RESULTS: Histopathologic evidence confirmed the development of AP. Marked changes were observed in the pulmonary tissue. Compared with controls, the AP group displayed higher values for NO metabolites in pancreas and lungs, and thiobarbituric acid reactive substances in circulation. Glutathione was lower in pancreas and in circulation. Glutathione and NO were positively correlated in pancreas and lungs of controls but negatively correlated in circulation of experimental group. In the experimental group, plasma thiobarbituric acid reactive substances were negatively correlated with pancreas thiobarbituric acid reactive substances but positively correlated with pancreas NO.

CONCLUSION: NO increases in both pancreas and lungs in AP and NO contributes to the pathogenesis of AP under oxidative stress.

Oxidative damage to nuclear DNA in hyperthyroid rat liver: inability of vitamin C to prevent the damage

The effects of hyperthyroidism on oxidative DNA damage in liver tissue and modification by vitamin C supplementation were investigated in rats. Animals were rendered hyperthyroid by administration of L-thyroxine (0.4 mg/100 g food) for 25 d. In the plasma samples, T(3), T(4), and thyroid-stimulating hormone (TSH) were measured by radioimmunoassay and ascorbate spectrophotometrically. Oxidative damage to hepatic nuclear DNA was determined by measuring deoxy-guanosine (dG) and 8-oxodG by high-performance liquid chromatography with diode array detector electrochemical detection (HPLC-DAD-ECD). In hyperthyroidism, 8-oxodG/(10(5) dG) levels were significantly higher and plasma vitamin C levels lower than in control rats. The results of this experimental study show that oxidative damage to hepatic nuclear DNA increases in the hyperthyroid state and that vitamin C was not effective in preventing this damage.

Increased Formation of 8-Hydroxy-2’-Deoxyguanosine in Peripheral Blood Leukocytes in Bladder Cancer

INTRODUCTION

Reactive oxygen species-induced damage to DNA plays a major role in carcinogenesis.

METHODS

In order to estimate the level of oxidative damage in bladder cancer, 8-hydroxy-2'-deoxyguanosine (8-OHdG) was determined in DNA isolated from peripheral blood leukocytes of healthy adults and patients with superficial transitional cell carcinoma. Patients with transitional cell carcinoma of the bladder and control individuals were similar in age. In this study, the level of 8-OHdG in DNA in male subjects was measured by the high-performance liquid chromatography-electrochemical detector method.

RESULTS

The 8-OHdG levels in DNA from leukocytes of bladder cancer patients were significantly higher than those in controls.

CONCLUSION

Reduction of oxidative stress is thought to be a very important measure for primary prevention of bladder cancer.

Hyperuricemia in hypothyroidism: is it associated with post-insulin infusion glycemic response?

This experimental study was designed to examine whether hyperuricemia in hypothyroidism is associated with insulin resistance. For induction of hypothyroidism, rabbits (n = 12) were administered methimazole orally (75 mg/100 g food) for 30 days. T3, T4 and TSH values measured in plasma prior to and at the end of the experimentation period revealed the establishment of hypothyroidism. In the euthyroid and hypothyroid states of rabbits, crystalline porcine insulin was administered (0.1 unit/kg body weight) intraperitoneally and plasma glucose was measured at 0, 15, 30, 45 and 60 minutes. Sum of post insulin infusion glucose values was considered to reflect insulin resistance. Creatinine clearance (GFR) and uric acid clearance (CuA) were determined. Additionally, triglycerides were measured in plasma and Mg2+ both in erythrocytes and in plasma. Due to hypothyroidism: i) The glycemic response to insulin was not altered. ii) GFR and CuA were both decreased but CuA/GFR unchanged. iii) Triglycerides in plasma decreased. iv) Mg2+ concentration increased in plasma whereas decreased in erythrocytes. Several associations were observed between the variables on correlation analysis. On the basis of our data, it could be suggested that insulin resistance does not exist in hypothyroidism. Hyperuricemia observed in hypothyroidism should be considered to be secondary to decreased renal excretion but not as an indicator of insulin resistance.

Biochemical evaluation of oxidative stress during exercise in patients with coronary heart disease

The impact of exercise tolerance test on oxidative stress was assessed by thiobarbituric acid reactive substances and markers of antioxidant status, namely Cu Zn superoxide dismutase, glutathione peroxidase, glutathione and vitamin E in blood samples of patients with exertional angina. The study was aimed to differentiate patients with positive exercise test (coronary heart disease patients) from patients with negative exercise test, at rest and peak exercise with respect to the investigated variables. Significantly lower values for both glutathione peroxidase activity and glutathione level were observed in patients after exercise test (p<0.01 and p<0.05, respectively). Only the patients with positive exercise test had significantly lower values for Cu Zn superoxide dismutase, glutathione peroxidase and glutathione, and a significantly higher ratio of thiobarbituric acid reactive substances/glutathione after exercise, as compared to before (p<0.05, p<0.05, p<0.05, p<0.01, respectively). Our findings indicate that the exercise test applied to patients with exertional angina oxidatively stresses the erythrocytes to a greater extent in exercise test (+) patients than in exercise test (-) patients.

Secondary venous ischemic injury associated with neutrophil infiltration and lipid peroxidation: amelioration of injury by cyclosporin A in a rat inguinal island flap

Secondary venous ischemia caused by anastomotic failure is one of the major causes of failure after free tissue transfers and replantations. The effects of cyclosporin A (CsA) on secondary ischemic injury associated with neutrophil infiltration and lipid peroxidation were evaluated in a rat inferior epigastric island skin flap model. Primary ischemia was produced by arteriovenous occlusion for 2 hours. Twenty-four hours later, secondary venous ischemia was produced by 5 hours of venous occlusion. Nonischemic (n = 5), primary ischemic (n = 5), and secondary ischemic control groups (n = 10), and four treatment groups (n = 10) were created. Treatment groups received either 15 or 30 mg per kilogram per day oral CsA for 3 days before flap elevation, or 15 or 30 mg per kilogram intravenous CsA at 4 hours of secondary venous ischemia. Flap survival area, malondialdehyde (MDA) content, and myeloperoxidase (MPO) activity were assayed for each group. The mean flap survival area of the high-dose posttreatment group was significantly higher than the secondary ischemic control group (29% +/- 39% vs. 3% +/- 8%; p < 0.05, Student's t-test). The MDA and MPO levels of each treatment group were significantly lower than the secondary ischemic control group at hours 1 and 24 (p < 0.0001, Student's t-test). The lowest MDA and MPO levels were achieved in the high-dose posttreatment group. Results suggest that CsA may improve flap survival after secondary venous ischemia by attenuating neutrophil infiltration and by reducing lipid peroxidation.

Calcium, magnesium, and zinc status in experimental hypothyroidism

In this study, experimental hypothyroidism was established and used to investigate possible alterations in the calcium, magnesium, and zinc homeostasis by assessing their concentration in plasma and erythrocytes. Hypothyroidism was induced by administration of methimazole an iodine blocker at a dose of 75 mg/100 g food for 3 wk. In the methimazole-induced hypothyroid state, the experimental animals showed a significant decrease in plasma zinc concentration, whereas a significant increase in plasma magnesium concentration occurred. No change was observed in plasma calcium concentration. The erythrocyte zinc and calcium concentrations were found to be increased, whereas magnesium concentration decreased. Erythrocyte magnesium concentration showed a significant positive correlation with T4 values. The study provides evidence for marked alterations in homeostatis of zinc, magnesium, and calcium.

Calcium, magnesium, and zinc status in experimental hyperthyroidism

In this study, experimental hyperthyroidism was established and used to investigate possible alterations in the calcium (Ca), magnesium (Mg), and zinc (Zn) homeostasis by assessing their concentrations in plasma and erythrocytes. In the L-thyroxine-induced hyperthyroidism condition, the experimental animals show a significant decrease in erythrocyte Ca, Mg, and Zn concentrations, and a significant decrease in plasma Mg concentration. Significant positive correlations were found for Mg and Zn both in plasma and in erythrocytes. The results suggest that the homeostasis of Ca, Mg, and Zn is altered during experimental hyperthyroidism.