Influence of methionine upon the activity of antioxidative enzymes in the kidney of rats exposed to sodium fluoride.

The intensified or uncontrolled formation of reactive oxygen species leads to disturbances of numerous biochemical processes. Among the factors inducing intensified free radical processes, fluoride ions are listed, among others. One of the organs most exposed to the toxic activity of fluorides is the kidney. In the study presented here, the influence of fluorine upon the activity of selected antioxidant enzymes in rat kidney has been examined, as well as antioxidant properties of methionine during intoxication with sodium fluoride. The experiment was carried out on Wistar FL rats (adult females) that for 35 days were administered water, NaF, NaF with methionine (doses: 10 mg NaF/kg bw/day, 10 mg Met/kg bw/day) . The influence of administered NaF and Met upon the antioxidative system in kidney was examined by analyzing the activity of the most important antioxidative enzymes (SOD, CAT, GPX, GR, GST). The studies carried out confirmed the disadvantageous effect of NaF upon the antioxidative system in rats (decrease in activity of antioxidative enzymes). Methionine increased the activity of antioxidative enzymes, most efficiently that of GPX, GR, and GST.

Influence of methionine upon the concentration of malondialdehyde in the tissues and blood of rats exposed to sodium fluoride.

The aim of the study has been to determine the influence upon the kidney, liver, and the blood prooxidative system, exercised by administration of methionine (Met), under conditions of oxidative stress induced by sodium fluoride (NaF).The experiment was carried out on Wistar FL rats (adult females) that, for 35 days, were administered distilled water, NaF or NaF with methionine (doses: 10 mg NaF/kg bw/day, 10 mg Met/kg bw/day). The influence of administered NaF and Met was examined by analyzing the concentration of malondialdehyde (MDA) in kidney, liver, erythrocytes, and blood plasma.The study confirmed the disadvantageous effect of NaF upon the antioxidative system in rats (an increase in the concentration of MDA).The administration of methionine reduced the process of lipid peroxidation (a decreased in the concentration of MDA). The best antioxidative properties have been demonstrated by methionine in rat liver.

The influence of rich-in-cholesterol diet and fluoride ions contained in potable water upon the concentration of malondialdehyde and the activity of selected antioxidative enzymes in rabbit liver.

Two experiments have been carried out, each on 18 (male) rabbits of the New Zealand breed. In each of them, animals were divided into three groups of six: control group, cholesterol group (CH), and cholesterol + fluoride group (CH+F). Experimental hypercholesterolemia has been induced in the animals with the diet enriched with 0.5 and 2 g% of cholesterol/100 g of fodder/24 h. The rabbits from CH+F groups have also been administered fluoride ions contained in drinking water (3 mg F(-)/kg of body mass/24 h). The influence of fluoride ions upon the concentrations of malondialdehyde (MDA) and activity of antioxidative enzymes, superoxide dismutase (SOD), mitochondrial enzyme (MnSOD), cytoplasmatic enzyme (ZnCuSOD), and glutathione peroxidase (GPX), has been examined in liver of rabbits. An increase (in comparison with cholesterol groups) in the concentration of MDA in both (CH+F) groups in rabbit liver has been noted. Moreover, a decrease (statistically significant) of SOD and MnSOD has been found in cholesterol groups, as well as in groups (CH+F) in comparison with control group. Furthermore, a decrease in the activity of SOD under the influence of F(-) together with increased activity of MnSOD (statistically significant in comparison with cholesterol groups) have been observed. The activity of ZnCuSOD increased in statistically significant manner in (CH) groups vs control group and decreased (statistically significantly in relation to cholesterol groups) under the influence of F(-).

The influence of fluoride ions upon selected enzymes of protein metabolism in blood plasma of rabbits with hypercholesterolemia.

Three-month studies were performed on 18 adult rabbits of New Zealand breed divided into three groups, with six animals in each: a control group on standard diet, a cholesterol group receiving 500 mg of cholesterol/100 g of feed per rabbit per 24 h (CH group), and a cholesterol + fluorine group (CH + F group) receiving 500 mg of cholesterol/100 g of feed per rabbit per 24 h and 3 mg of F(-)/kg of body weight per 24 h. The conducted studies proved that cholesterol in the applied dosage (500 mg cholesterol per rabbit per 24 h) has an atherogenic action. Fluoride ions administered together with a 500-mg cholesterol atherogenic diet inhibit the atheromatosic changes in the aorta. The concentration of plasma cholesterol was elevated in both study groups when compared to the control group but decreased in the CH + F group when compare to the CH group. The influence of fluoride ions has been examined upon the activity of alanine aminotransferase, aspartate aminotransferase, and glutamate dehydrogenase (GLDH) in the plasma in the liver of rabbits in the course of experimental hypercholesterolemia. Increase in the activity of study enzymes has been observed in the blood plasma, which may be due to damage occurring to hepatocytes of the animals examined (a statistically significant increase in the activity of GLDH in the plasma). In the liver, the inhibition of activity for all examined enzymes has been observed in the group of rabbits with hypercholesterolemia, which testifies the disturbances in protein metabolism in examined animals. The addition of sodium fluoride to the diet rich in cholesterol results in "removing the block" on those activities, which increase. We suppose that the permeability of the hepatocyte membrane was elevated, so the activities of examined enzymes increased in the plasma ("escape" to plasma). On the one hand, fluoride ions result in probable lesion of hepatocytes membranes; on the other hand, they inhibit the atheromatosic changes in the aorta.

Assessment of semen function and lipid peroxidation among lead exposed men.

The study population included healthy, fertile men, employees of Zinc and Lead Metalworks (n=63). Workers exposed to lead were divided into two groups: a group with moderate exposure to lead (ME) - blood lead level (PbB) 25-40 microg/dl and a group with high exposure to lead (HE) PbB=40-81 microg/dl. The control group consisted of office workers with no history of occupational exposure to lead. Evaluation of lead, cadmium and zinc level in blood and seminal plasma, zinc protoporphyrin in blood (ZPP), 5-aminolevulinic acid in urine (ALA), malondialdehyde (MDA) in seminal plasma and sperm analysis were performed. No differences were noted in the concentration of cadmium and zinc in blood and seminal plasma in the study population. Lipid peroxidation in seminal plasma, represented as MDA concentration, significantly increased by about 56% in the HE group and the percentage of motile sperm cells after 1 h decreased by about 34% in comparison to the control group. No statistically significant correlation between other parameters of sperm analysis and lead exposure parameters nor between lead, cadmium and zinc concentration in blood and seminal plasma were found. A positive association between lead intoxication parameters (PbB, ZPP, lead seminal plasma) and MDA concentration in sperm plasma and inverse correlation with sperm cells motility (PbB, ZPP) was found. An increased concentration of MDA was accompanied by a drop in sperm cells motility. In conclusion, we report that high exposure to lead causes a decrease of sperm motility in men most likely as a result of increased lipid peroxidation, especially if the level in the blood surpasses the concentration of 40 microg/dl.

Influence of fluoride on rat kidney antioxidant system: effects of methionine and vitamin E.

The aim of the study has been to determine and compare the influence upon the kidney antioxidative system, exercised by administration of vitamin E, and vitamin E in combination with methionine, under conditions of oxidative stress induced by sodium fluoride. The experiment was carried out on Wistar FL rats (adult males) that, for 35 days, were administered water, NaF, NaF with vitamin E, or vitamin E with methionine (doses: 10 mg NaF/kg of body mass/24 h, 3 mg vitamin E per 10 microl per rat for 24 h, 2 mg methionine per rat for 24 h). The influence of administered sodium fluoride and antioxidants upon the antioxidative system in kidney was examined by analyzing the concentration of malondialdehyde (MDA) and the activity of the most important antioxidative enzymes (SOD, total and both its isoenzymes, GPX, GST, GR, and CAT). The studies carried out confirmed the disadvantageous effect of the administered dose of NaF upon the antixodiative system in rats (increase in the concentration MDA, decrease activity of all antioxidative enzymes). The administration of vitamin E increased the activity of studied enzymes with the exception of glutathione reductase GR; it also reduced the processes of lipid peroxidation. It has been found that combined doses of vitamin E and methionine were most effective in inhibiting lipid peroxidation processes. The results confirmed the antioxidative properties of methionine.

The influence of methionine, selenomethionine, and vitamin E on liver metabolic pathways and steatosis in high-cholesterol fed rabbits.

Significant disorders of liver metabolic pathways enzymes after high-cholesterol diet could give information on liver steatosis development. This process could probably also be inhibited by some compounds, as examined in rabbits. Forty-two male rabbits were served a high-cholesterol diet (2 g%) (0.67 g/kg b.m./24 h) with addition of d,l-methionine (70 mg/kg b.m./24 h) or seleno-d,l-methionine (12.5 microg/kg b.m./24 h) or alpha-tocopherol (10 mg/kg b.m./24 h) for 3 months to compare the protection effect of used compounds on liver metabolism and steatosis. At the beginning and every month, blood was taken. After the experiment was completed, livers were dissected for histological examinations. The concentration of total cholesterol (t-CH), triacylglycerol (TG), and the activities of aldolase (ALD), sorbitol dehydrogenase (SDH), glutamate dehydrogenase (GLDH), lactate dehydrogenase (LDH), aspartate aminotransferase (AST), and alanine aminotransferase (ALT) were determined. Plasma t-CH and TG concentrations were significantly higher in all experimental groups vs control group. Blood serum AST and ALT activities did not undergo change but there were observed not significant increase in the CH group vs control group. Activities of SDH, GLDH, and LDH increased in blood serum and decreased in the liver in all experimental groups. Activities of LDH and SDH increased in the liver in the CH+Met group vs CH group. ALD activity decreased in the liver only in the CH and CH+Se groups. This data support a lipotoxic model of cholesterol-mediated hepatic steatosis. Prolonged administration of high-cholesterol diet not only disturbs the structure of cell membranes, which is expressed by decreased activity of enzymes in the liver and the migration of those enzymes to plasma but as well leads to steatosis of the liver, which has been confirmed by histological examinations. The applied compounds appear to have a varying influence upon the activity of enzymes determined in serum and liver. Obtained results showed a beneficial influence of methionine and vitamin E supplementation on liver steatosis development.

Influence of sodium fluoride and caffeine on the concentration of fluoride ions, glucose, and urea in blood serum and activity of protein metabolism enzymes in rat liver.

The aim of the study was examining the effect of fluoride ions and caffeine administration on glucose and urea concentration in blood serum and the activity of protein metabolism enzymes and selected enzymes of the urea cycle in rat liver. The study was carried out using 18 male Sprague-Daowley rats (4.5 mo old). Rats were divided into three groups. Group I received distilled water ad libitum. Group II received 4.9 mg F-/kg body mass/d of sodium fluoride in the water, and group III received sodium fluoride (in the above-mentioned dose) and 3 mg/kg body mass/d of caffeine in the water. After 50 d, the rats were anesthetized with thiopental and fluoride ions, glucose, and urea concentration in blood serum were determined. Also determined were the activities of aspartate aminotransferase, alanine aminotransferase glutamate dehydrogenase, ornithine carbamoylotransferase and arginase in liver homogenates. Liver was taken for pathomorphological examinations. The applied doses of F- (4.9 mg/kg body mass/d) and F- + caffeine (4.9 mg F-/kg body mass/d + 3 mg caffeine/kg body mass/d) resulted in a statistically significant increase of fluoride ion concentration in blood serum, a slight increase of the glucose concentration, and no changes in the concentration of urea in blood serum. This might testify to the absence of kidney lesions for the applied concentrations of F-. No change in the functioning of hepatocytes was observed; however, slight disturbances have been noted in the functioning of the liver, connected with the activation of urea cycle, increase of arginase activity, and accumulation of F- in this organ. There was no observed significant influence of caffeine supplementation on the obtained results.

Influence of sodium fluoride and caffeine on the kidney function and free-radical processes in that organ in adult rats.

An experiment was carried out on Sprague-Dawley rats (adult males) that for 50 days were administered, in the drinking water, NaF and NaF with caffeine (doses, respectively: 4.9 mg of NaF/kg body mass/24 h and 3 mg of caffeine/kg body mass/24 h). Disturbances were noted in the functioning of kidneys, which were particularly noticeable after the administration of NaF with caffeine. Changes in the functioning of kidneys were also confirmed by such parameters as the level of creatinine, urea, protein, and calcium. Modifications of the enzymatic antioxidative system (superoxide dismutase, catalase, and glutathione peroxidase) and lipid peroxidation (malondialdehyde) were also observed. Changes in the contents of the above parameters as well as pathomorphological examinations suggest increased diuresis, resulting in dehydration of the rats examined.

[The effect of caffeine and sodium fluoride on fluoride concentration in serum and its content in teeth and bones of rats]. / Wplyw kofeiny i fluorku sodu na stiezenie fluorków w surowicy krwi i ich zawartosc w zebach i kosciach szczurów.

PURPOSE: The aim of this work was to determine the effect of sodium fluoride at a dose of 4.9 mg/kg b.w./24 h and caffeine at a dose of 3 mg/kg b.w./24 h on the concentration of fluoride in serum and its content in teeth and bones of rats. MATERIAL AND METHODS: The study was done in 18 male Sprague-Dawley rats. CONCLUSIONS: A negative effect of caffeine administered concurrently with sodium fluoride on teeth and bones of rats was demonstrated as reflected by a tendency to increased content of fluoride in bones and decreased content in teeth.

[The effect of sodium fluoride and caffeine on concentrations of calcium, phosphorus and magnesium in rat serum]. / Wplyw fluorku sodu i kofeiny na stezenie wapnia, fosforu i magnezu w surowicy krwi szczurów.

PURPOSE: The aim of this study was to examine the effect of sodium fluoride and caffeine on concentrations of calcium, phosphorus, and magnesium in rat serum. MATERIAL AND METHODS: The experiment was carried out in adult male Sprague-Dawley rats. Rats were divided into three groups of six rats. In the control group, animals received distilled water. In study group I, water was supplemented with sodium fluoride (4.9 mg F-/kg b.m./24 h), while study group II received sodium fluoride (4.9 mg F-/kg b.m./24 h) and caffeine (3 mg/kg b.m./24 h). RESULTS: Significantly higher calcium concentrations in serum were noted after exposure to NaF and caffeine. There was a tendency to higher levels of calcium in group I. Biochemical analysis of rat serum showed unchanged concentrations of magnesium and phosphorus vs. control. In conclusion, the dose of caffeine used by us had no effect on serum markers of mineral metabolism in hard tissues.

[Effect of sodium fluoride on the activity of sorbitol dehydrogenase in plasma and liver of rabbits with experimental atherosclerosis]. / Wplyw fluorku sodu na aktywnosc dehydrogenazy sorbitolowej w osoczu i watrobie królików z doswiadczalna miazdzyca.

This study was done in rabbits placed on a low-cholesterol (0.5 g%) and high-cholesterol (2.0 g%) diet to induce experimental atherosclerosis. The intake of fluorine in the form of NaF in water was 3 mg F(-)/kg b.w./24 h. The activity of sorbitol dehydrogenase (SDH) was increased in plasma and decreased in the liver of rabbits on the high-cholesterol diet and in animals simultaneously exposed to NaF in water. Two months of the low-cholesterol diet produced an increase in SDH activity in plasma as a direct consequence of exposure to fluoride in the diet and presumably caused by accumulation of fluoride in the liver.

[Activities of some enzymes and concentration of ammonia in serum of rats with fluoride hyperglycemia]. / Aktywnosc wybranych enzymów i stezenie amoniaku w surowicy krwi szczurów z hiperglikemia fluorkowa.

The study was done in 30 one-month-old Wistar FL rats divided into one control and two study groups of ten animals each. Hyperglycemia was induced with sodium fluoride in water at a concentration of 50 or 100 mg/L during four months. Control animals received distilled water. We observed significantly (p < 0.05) reduced activities of aspartate aminotransferase (by 22.8%) and malic dehydrogenase (by 10.9%) in the group exposed to 100 mg F(-)/L. No pathological changes were revealed in the pancreas of exposed animals.

Activity of pancreatic antioxidative enzymes and malondialdehyde concentrations in rats with hyperglycemia caused by fluoride intoxication.

The aim of this work was to examine the effect of fluoride ions on antioxidative enzyme activity in the pancreas of rats exposed during 4 months to NaF in drinking water. The study was carried out in 30 four-week-old male Wistar FL rats, that were randomly assigned to three equal groups and given distilled water ad libitum for three weeks. Subsequently, two examined groups of animals were exposed to NaF in drinking water: group 1 (10 rats) at 50 mg F(-)/L (2.63 mmol/L), group 2 (10 rats) at 100 mg F(-)/L (5.26 mmol/L). The control group (10 rats) received distilled water. After 4 months the animals were anesthetized with ether prior to collection of pancreas and cardiac blood. Serum concentrations of glucose and fluoride, as well as activities of the cytoplasmic (CuZn-SOD) and the mitochondrial (Mn-SOD) superoxide dismutase, glutathione peroxidase (GSH-Px) and concentrations of malondialdehyde (MDA) in the homogenized pancreas were measured. The activity of CuZn-SOD was reduced by 50% and a tendency to lower activities of Mn-SOD was observed. No changes were noted in the activity of GSH-Px or concentrations of MDA. We conclude that: 1) the fluoride caused hyperglycemia in rats in this study is not accompanied by an activation of the free radical production in the pancreas; 2) the hyperglycemia in the exposed rats cannot be attributed to pancreatic damage caused by fluoride ions (the cause in this case appears to be extrapancreatic); 3) the inhibition of pancreatic CuZn-SOD is probably due to the direct action of fluoride on the enzyme.