Cadmium, copper and zinc in tissues of deceased copper smelter workers

Workers at a copper and lead smelter in northern Sweden have a multifactorial exposure to a number of heavy metals. The concentrations of cadmium, copper and zinc in liver, lung, kidney and brain tissues have been determined by atomic absorption spectrometry in 32 deceased long-term exposed male lead smelter workers, and compared with those of 10 male controls. Furthermore, copper and zinc levels in hair and nails were determined by energy-dispersive X-ray fluorescence.

The highest cadmium concentrations among both workers and controls were observed in kidney, followed in order by liver, lung and brain. The levels in kidney, liver and lung were all significantly higher in the workers than in the controls (p < 0.03). Among the workers relatively strong positive correlations (p < 0.03) were observed between cadmium concentrations in liver and lung, liver and kidney, liver and brain, and lung and brain. In the exposed workers a positive correlation was observed between cadmium and zinc concentrations in the kidney (r_s = 0.38; p = 0.034). This is probably mainly due to the protein metallothionein, which is stored in the kidney, binding equimolar amounts of these two metals.

The highest concentrations of copper were found in hair and nails among both workers and controls, followed in order by liver, brain, kidney and lung. The tissue concentrations of copper in brain, lung and kidney were all significantly higher among the smelter workers than in the controls (p ≤ 0.036). Copper levels in lung and age at time of death were positively correlated among the exposed workers (r_s = 0.39; p = 0.029). In the same group, positive correlations between copper and zinc concentrations in kidney (r_s = 0.45; p = 0.009) and nails (r_s = 0.68; p < 0.001) were also observed, reflecting possible biological interactions between these two metals.

Among both workers and controls, the highest zinc concentrations were found in hair, followed in order by nails, liver, kidney, brain and lung. Significantly higher tissue concentrations among the workers as compared with the reference group were noted in kidney, liver and brain (p ≤ 0.033).

Neither copper nor zinc concentrations in hair and nails seemed to provide a useful measure of the trace element status of the smelter workers.     

Potentiation of DOM-induced stimulus control by fluoxetine and citalopram: role of pharmacokinetics

The present investigation examined the interaction between 2,5-dimethoxy-4-methylamphetamine [DOM] and the selective serotonin reuptake inhibitor [SSRI] citalopram in rats trained with DOM [0.6 mg/kg; 75 min pretreatment time] as a discriminative stimulus. Pretreatment with citalopram at a dose of 1.0 mg/kg shifted the DOM dose response relationship to the left. Unlike previously tested SSRI's, the enhancement of DOM-induced stimulus control occurred in the absence of significant partial substitution by citalopram. DOM brain levels were measured using a GC-MS method both in the presence and absence of citalopram and fluoxetine in order to evaluate the pharmacokinetic contribution to the observed behavioral effect. The data indicated that fluoxetine but not citalopram significantly increased DOM brain levels. It is concluded that the effects of DOM as a discriminative stimulus are potentiated by the acute administration of citalopram and this effect is not mediated by additivity or pharmacokinetic mechanisms.     

Development of a two-step injector for GC-MS with on-column derivatization, and its application to the determination of amphetamine-type stimulants (ATS) in biological specimens

A two-step auto-injector has been developed for the automated on-column derivatization and subsequent GC-MS of amine-type drugs and metabolites. To effectively derivatize such analytes, this injector has been designed to inject the derivatization reagent several seconds after the sample has been injected. Eleven kinds of amphetamine-type stimulants (ATS) and their typical metabolites were examined, using the trifluoroacetylation reagent N-methyl bis(trifluoroacetamide) (MBTFA). Although the quantitative derivatization of the hydroxyl groups was difficult, this technique was successfully applied to the determination of ATS in urine, blood, and hair specimens. The detection limits of methamphetamine and amphetamine in hair were 0.2 and 0.1 ng/mg hair, respectively, in the full-scan mode, when a 10 mg hair sample is analyzed.     

Determination of p-trifluoromethylphenol, a metabolite of fluoxetine, in tissues and body fluids using an electron-capture gas chromatographic procedure

An electron-capture gas chromatographic procedure was developed for the analysis of p-trifluoromethylphenol, an O-dealkylated metabolite of fluoxetine, in biological samples. A basic extraction of the biological sample was employed, followed by derivatization with pentafluorobenzenesulfonyl chloride. The internal standard, 2,4-dichlorophenol, was added to all samples used in the procedure to aid in quantitation. The practical limit of detection (signal-to-noise ratio>3) for p-trifluoromethylphenol was <5 ng/ml in human plasma samples, <10 ng/g of rat brain tissue, <25 ng/g of rat liver tissue and <25 ng/ml in human and rat urine samples. In the rat, the levels of free p-trifluoromethylphenol in the liver were 10-fold higher than those in the brain, and a substantial amount was excreted in the urine. Human urine samples contained levels of free p-trifluoromethylphenol approximately 30-fold higher than those found in human plasma samples. The procedure described is useful for the detection and quantitation of free p-trifluoromethylphenol in humans and rats treated with fluoxetine.     

No Specific Effect of Fluoxetine Treatment on Fasting Glucose,Insulin, Lipid Levels,and Blood Pressure in Healthy Men with Abdominal Obesity

In this paper we investigated the effect of fluoxetine (60 mg/d) on serum lipids, glucose and insulin concentrations and blood pressure by means of a randomized, double-blind placebo controlled trial. Thirty-eight overweight BMI: 26–30 kg/m²), nondiabetic, nonhypertensive men with an abdominal fat distribution (waist/hip ratio: >0.97) received dietary advice and placebo or fluoxetine for 12 weeks. The changes in serum parameters and blood pressure in the fluoxetine treated group were not different from the placebo treated group, despite a significantly larger weight loss in the fluoxetine group. In both groups serum total-cholesterol concentrations, serum LDL-cholesterol concentrations and tlie HDL/LDL ratio were significantly improved after treatment. Reductions in fasting glucose concentration and systolic blood pressure were only significant in the placebo group. A reduction of serum triglycerides and an increase of HDL-cholesterol were found in the fluoxetine treated group. In the total study population the changes in serum lipids seemed to be more strongly related to the change in total body fat or subcutaneous abdominal fat (assessed by MRI) compared to the change in visceral fat. The improvement of most of the serum lipids was related to tlie change in total body fat independent of the mechanism for attaining this fat loss. Our results indicate that fluoxetine treatment has no specific effect beyond that expected for weight loss on serum lipid, glucose and insulin concentrations, and blood pressure in overweight men.     

Selenium content and distribution in rat tissues irradiated with gamma rays

The effects of supplementation with selenous yeast and ionizing radiation on selenium (Se) content and distribution were evaluated in rat tissues (liver, kidney, spleen, heart, muscle, blood, front brain, hind brain, hypothalamus, pituitary, adrenal glands, testes, and hair). This study had 16 Se-supplemented (0.5 μg Se/d) and 16 placebo adult male Wistar rats. One half of the animals (eight Se-supplemented and eight placebos) were irradiated with a single dose of 4.2 Gy from a Co-60 source and sacrificed 7 d after irradiation along with nonirradiated animals and analyzed for Se content determination. The data obtained showed that selenous yeast supplementation increased Se levels in rat tissues (highest increases in hypothalamus, 161%; hind brain, 126%; spleen, 110%; and adrenal gland, 105%). Ionizing radiation induced significant changes in Se content and distribution (decrease in liver, blood, hair, femoral muscle, spleen, and hypothalamus; increase in kidney, testes, adrenal glands, and brain of placebo group). Supplementation with selenous yeast reduces changes in Se content and distribution after irradiation. It seems that the animal tissue susceptibility to oxidative damage may be correlated to their ability to retain Se in tissues.     

Simultaneous quantification of opiates, amphetamines, cocaine and metabolites and diazepam and metabolite in a single hair sample using GC-MS

A method is described for the simultaneous identification and quantification of opiates, amphetamines, cocainics, diazepam and nordiazepam from one hair extract (typically 10-50mg hair). After decontamination by washing with shampoo, dichloromethane, isopropanol and acetone, drugs were extracted using 0.1M HCl followed by SPE clean-up using mixed-mode extraction cartridges. The SPE extracts were submitted to a two-step derivatisation using MBTFA and MSTFA+1% TCMS and analysis was performed by GC-MS using both SIM and scan modes. Four deuterated standards were used to monitor 14 compounds. The limit of quantification was the total drug detected from the sample. This was 5 ng for amphetamines and 10 ng for remaining drugs which is equivalent to 0.1 and 0.2 ng/mg from a 50mg sample. Standard curves for the range 5-400 ng total drug concentration for all drugs had regression coefficients greater than 0.98. An authentic hair sample was used to validate the method and gave R.S.D.s <25% for both inter and intra-day reproducibility. The results of the analysis of hair taken from four patients attending a drug treatment clinic and six hair samples including head hair, pubic hair, axial hair and beard taken at post-mortem are presented.     

Cosinor analysis of diurnal changes of the reduced glutathione level in the blood, brain, liver and kidneys of mice, induced by ACTH administration

The influence of a single dose of ACTH(100 I.U. /kg body weight) on the diurnal rhythm of reduced glutathione (GSH) was studied in the blood and brain, liver and kidney homogenates of male mice. Cosinor analysis revealed that ACTH induces changes in the mean diurnal amount of GSH in the blood, brain, liver and kidneys. At the same time, GSH amplitudes in the blood and kidneys increased significantly, whereas in the case of brain and liver they decreased markedly. Moreover, it was found that ACTH induces a shift in GSH acrophases in the blood, brain, liver and kidneys as compared with the control values.     

A relationship between vitamin B12, folic acid, ascorbic acid, and mercury uptake and methylation

Ingestion of megadoses of certain vitamins appears to influence the in vivo methylation of mercuric chloride in guinea pigs. The addition of megadoses of vitamin B12 fed either singularly or in combination with folic acid resulted in increased methylmercury concentrations in the liver. Moreover, percent methylmercury levels were significantly increased with B12 treatment in the liver (B12 only and B12/folic acid) and brain (B12/vitamin C). Incorporation of high levels of folic acid into the dietary regime also increased the methylmercury concentration particularly in the liver and hair tissues. The addition of vitamin C in the diet, particularly in combination with B12 (brain) or folic acid (muscle) resulted in increased methylmercury levels in these tissues and percent methylmercury values with B12 in the muscle and brain tissue.     

Comparison of catechol-Q-methyltransferase from rat brain, erythrocytes and liver.

Catechol-O-methyltransferase activity from supernatant of brain, red blood cells and liver of the rat were characterized by the following items: 1) substrate specificity with respect to five catechol substrates, 2) meta/para ratio of O-methylation, 3) apparent Michaelis constants, 4) pH dependence of reaction rate. Under identical conditions, a progressive decrease in the rate of O-methylation by rat liver supernatant can be noticed in the sequence of 3.4-dihydroxy-acetophenone > 3.4-dihydroxybenzoic acid > 3.4-dihydroxyphenylacetic acid. Using 3.4-dihydroxybenzaldehyde as substrate, the meta/para ratio of O-methylation and the apparent Michaelis constants are similar for catechol-O-methyltransferase from brain and red blood cells and differ from the values obtained with liver supernatant. In phosphate buffer, the pH curves are almost identical for catechol-O-methyltransferase from brain, red blood cells and liver, in glycine/NaOH buffer, however, the liver enzyme shows a broad peak. From our experiments it is obvious that the biochemical characteristics selected are similar for soluble catechol-O-methyltransferase from brain and erythrocytes which differ from that obtained with liver enzyme.     

Levels and distribution of zinc,copper, magnesium,and calcium in rats fed different levels of dietary zinc

Effects of altered dietary zinc on levels of zinc, copper, magnesium, and calcium in organ and peripheral tissues were studied. When rats fed a zinc-deficient diet (1.3 μg Zn/g) for 28 d were compared with rats fed a control diet (37.5 μg Zn/g), levels of zinc were slightly lower in plasma, hair, and skin and 50% lower in femur and pancreas, whereas the levels of copper were higher in all tissue except plasma. Magnesium levels were higher than controls in the heart and lower in the spleen, whereas the calcium levels were lower in plasma, lung, spleen, kidney, and skin and strikingly higher in brain, hair, and femur. When rats fed a zinc-supplemented diet (1.0 mg Zn/g) were compared to the same conrols, levels of zinc in these were higher in all organs and peripheral tissues studied, except heart, lung, and liver; copper levels were higher in liver, kidney, and spleen; magnesium levels were significantly higher in the spleen, but were little affected in other tissues, although calcium levels were higher in pancreas, spleen, kidney, and skin and lower in plasma and hair. These data indicate that overall copper organ and peripheral tissue levels are affected inversely, and zinc and calcium levels directly, by zinc nutriture.     

Analysis of selenium in bovine liver by gas chromatography with mass-selective, electron-capture and nitrogen-phosphorus detection

The concentration of selenium (Se) in liver was determined by gas chromatography (GC) with mass-selective (GC-MS), electron capture (GC-ECD) and nitrogen-phosphorus (GC-NPD) detection. Liver samples were digested in a mixture containing HNO₃ and Mg(NO₃). Se^VI was converted to Se^IV. Se^IV was derivatized with 4-nitrophenylenediamine and then extracted in toluene. A 1-μl volume of the toluene extract was analyzed by the GC-MS, GC-ECD or GC-NPD methods. The detection limits of the GC-ECD, the GC-NPD and the GC-MS methods were 25, 50 and 800 pg, respectively. The GC-NPD method was more selective for the derivatized Se than the GC-ECD method. The GC-MS method had the advantage of using the ⁷⁶Se isotope as the internal standard. Se concentrations in liver samples determined by the three methods were comparable.     

Simultaneous determination of fluoxetine and its metabolite p-trifluoromethylphenol in human liver microsomes using a gas chromatographic-electron-capture detection procedure

An gas chromatography-electron-capture detection method has been developed for simultaneous determination of fluoxetine and p-trifluoromethylphenol (TFMP), an O-dealkylated metabolite of fluoxetine in human liver microsomes. Prior to the analysis, aliquots of alkalinized microsomal mixture were extracted with ethyl acetate solvent containing acetonitrile (10%, v/v) and the derivatizing reagent, pentafluorobenzenesulfonyl chloride (0.1%, v/v). The organ phase was retained and taken to dryness, the residue was reconstituted in methanol, and the aliquot of extracts was injected directly into a gas chromatograph equipped with an electron-capture detector. 2,4-Dichlorophenol was added to the initial incubation mixture and carried through the procedure as the internal standard. The method provided the mean recoveries of up to 103% for fluoxetine and 104% for TFMP. Acceptable relative standard deviations were found for both within-run and day-to-day assays. The practical limit of detection (signal-to-noise ratio=3) was 1.62 ng/ml for TFMP and 6.92 ng/ml for fluoxetine in human liver microsomes, and the limit of quantitation was 8.1 pg for TFMP and 34.6 pg for fluoxetine. The assay is rapid and sensitive and has been applied successfully to simultaneous quantification of fluoxetine and TFMP in human liver microsomes with different CYP2C19 genotypes.     

Fluoxetine exerts age-dependent effects on behavior and amygdala neuroplasticity in the rat

The selective serotonin reuptake inhibitor (SSRI) Prozac® (fluoxetine) is the only registered antidepressant to treat depression in children and adolescents. Yet, while the safety of SSRIs has been well established in adults, serotonin exerts neurotrophic actions in the developing brain and thereby may have harmful effects in adolescents. Here we treated adolescent and adult rats chronically with fluoxetine (12 mg/kg) at postnatal day (PND) 25 to 46 and from PND 67 to 88, respectively, and tested the animals 7–14 days after the last injection when (nor)fluoxetine in blood plasma had been washed out, as determined by HPLC. Plasma (nor)fluoxetine levels were also measured 5 hrs after the last fluoxetine injection, and matched clinical levels. Adolescent rats displayed increased behavioral despair in the forced swim test, which was not seen in adult fluoxetine treated rats. In addition, beneficial effects of fluoxetine on wakefulness as measured by electroencephalography in adults was not seen in adolescent rats, and age-dependent effects on the acoustic startle response and prepulse inhibition were observed. On the other hand, adolescent rats showed resilience to the anorexic effects of fluoxetine. Exploratory behavior in the open field test was not affected by fluoxetine treatment, but anxiety levels in the elevated plus maze test were increased in both adolescent and adult fluoxetine treated rats. Finally, in the amygdala, but not the dorsal raphe nucleus and medial prefrontal cortex, the number of PSA-NCAM (marker for synaptic remodeling) immunoreactive neurons was increased in adolescent rats, and decreased in adult rats, as a consequence of chronic fluoxetine treatment. No fluoxetine-induced changes in 5-HT_1A receptor immunoreactivity were observed. In conclusion, we show that fluoxetine exerts both harmful and beneficial age-dependent effects on depressive behavior, body weight and wakefulness, which may relate, in part, to differential fluoxetine-induced neuroplasticity in the amygdala.     

Simultaneous determination of citalopram, fluoxetine, paroxetine and their metabolites in plasma and whole blood by high-performance liquid chromatography with ultraviolet and fluorescence detection

A method for the simultaneous determination of the three selective serotonin reuptake inhibitors (SSRIs) citalopram, fluoxetine, paroxetine and their metabolites in whole blood and plasma was developed. Sample clean-up and separation were achieved using a solid-phase extraction method with C₈ non-endcapped columns followed by reversed-phase high-performance liquid chromatography with fluorescence and ultraviolet detection. The robustness of the solid-phase extraction method was tested for citalopram, fluoxetine, paroxetine, Cl-citalopram and the internal standard, protriptyline, using a fractional factorial design with nine factors at two levels. The fractional factorial design showed two significant effects for paroxetine in whole blood. The robustness testing for citalopram, fluoxetine, Cl-citalopram and the internal standard revealed no significant main effects in whole blood and plasma. The optimization and the robustness of the high-performance liquid chromatographic separation were investigated with regard to pH and relative amount of acetonitrile in the mobile phase by a central composite design circumscribed. No alteration in the elution order and no significant change in resolution for a deviation of ±1% acetonitrile and ±0.3 pH units from the specified conditions were observed. The method was validated for the concentration range 0.050–5.0 μmol/l with fluorescence detection and 0.12–5.0 μmol/l with ultraviolet detection. The limits of quantitation were 0.025 μmol/l for citalopram and paroxetine, 0.050 μmol/l for desmethyl citalopram, di-desmethyl citalopram and citalopram-N-oxide, 0.12 μmol/l for the paroxetine metabolites by fluorescence detection, and 0.10 μmol/l for fluoxetine and norfluoxetine by ultraviolet detection. Relative standard deviations for the within-day and between-day precision were in the ranges 1.4–10.6% and 3.1–20.3%, respectively. Recoveries were in the 63–114% range for citalopram, fluoxetine and paroxetine, and in the 38–95% range for the metabolites. The method has been used for the analysis of whole blood and plasma samples from SSRI-exposed patients and forensic cases.     

Comparative Study of Liver Cancer Patients in Arsenic Exposed and Non-exposed Areas of Pakistan

The investigated data shows that arsenic (As) in drinking water is associated with increased mortality from different types of cancers including liver cancer. In this study, blood and scalp hair samples of male liver cancer patients and healthy referents belonging to As exposed areas of Sindh Pakistan were analyzed for As contents. The As levels in drinking water of understudy area showed that sections of this population was exposed to 3-15-folds higher concentrations of As than permissible limit. For comparative purposes, blood and scalp hair samples of matched cancerous patient as referent patients belonging to big city (Hyderabad) who have used municipal treated water with low As levels <10?μg/L were also collected. The results of this study showed that the average As concentration was higher in the blood and scalp hair of exposed and non-exposed referent cancer patients as compared to referents (p?相似文献   

Serotonin content in different sections of the brain, liver, intestines and blood of rats predisposed and not predisposed to alcohol consumption

Experiments were made with white random-bred rats (males) exposed to ethanol. The content of serotonin measured by spectrofluorometry was higher in the hypothalamus, brain stem and intestine, and was lower in the thalamus, striatum liver and blood in the animals predisposed to voluntary alcohol consumption and with lateral position duration 62 +/- 18 min as compared with the animals not predisposed to alcohol consumption and with lateral position duration 196 +/- 23 min, the dose of ethanol being 4.5 g/kg i. p. Thirty minutes after ethanol administration in a dose of 2.5 g/kg i. p. to the alcohol-predisposed rats there was a lowering of the serotonin content in the hypothalamus and an increase in the thalamus, brain stem, liver and blood. Meanwhile in the rats not predisposed to alcohol consumption, the serotonin content rose in the hypothalamus, brain stem, liver, intestine and blood and fell in the thalamus and striatum. It is assumed that the serotoninergic system of the brain may play a role in the formation of "positive" or "negative" attitudes to ethanol in the population of white random-bred rats.     

Murine glycosyltransferases responsible for the expression of globo-series glycolipids: cDNA structures, mRNA expression, and distribution of their products

Biological functions of globo-series glycosphingolipids are not well understood. In this study, murine cDNAs of two glycosyltransferases responsible for the synthesis of globo-series glycolipids and mRNA expression of those genes were analyzed. Distribution of their products was also analyzed. Murine cDNAs for Gb3/CD77 synthase and Gb4 synthase predicted that both of them are type II membrane proteins with 348 and 331 amino acids, respectively. In northern blotting, Gb3/CD77 synthase gene was mainly expressed in kidney and lung but also detected in many other tissues. Gb4 synthase was expressed in brain, heart, kidney, liver, skin, and testis. In the immunohistological analysis, Gb3/CD77 was mainly expressed in the proximal tubules as revealed with coincidental expression with angiotensin-converting enzyme (ACE). In spleen, it was detected in pre-B cells in the peripheral region of the white pulp, as suggested with coincidental expression with CD10. It was also expressed on the endothelia of the alveolar capillaries in lung and on the sebaceous ducts aside of the hair follicles. Gb4 was also detected mainly on the proximal tubules in kidney and on the endothelia of the alveolar capillaries in lung as Gb3/CD77. But it was also detected on the epithelium of the bronchus, seminiferous tubules and tails of spermatozoa in testis, blood vessels of choroids plexus and endothelial cells in brain, and central and hepatoportal veins in liver. The expression patterns of two genes and their products almost corresponded with some exception. The results would provide essential information for the functional studies of globo-series glycolipids.     

Development of a diphasic dialysis method for the extraction/purification of residues of ethinylestradiol in hair of cattle, and determination by gas chromatography-tandem mass spectrometry

A confirmatory method for the analysis of ethinylestradiol extracted from cattle hair was developed. After the extraction of the xenobiotic from the hair, by using alkaline digestion, the purification of the extract was carried out by employing diphasic dialysis. For the optimization of the technique several parameters was evaluated such as pH, extraction solvents, temperatures, times and agitation speeds. The detection and confirmation of the steroid was accomplished by using a GC-MS2 ion trap system after trimethylsilylation. The calibration curve was linear over the range of 4-20 ng/g. The detection and quantification limit were 0.52 and 0.80 ng/g respectively; with recoveries up to 94%.     

Routine analysis of amphetamine and methamphetamine in biological materials by gas chromatography-mass spectrometry and on-column derivatization

A simple determination method of amphetamine (AP) and methamphetamine (MA) in biological materials was developed using on-column derivatization and gas chromatography-mass spectrometry (GC-MS). AP and MA in biological materials were adsorbed on the surface of Extrelut and then extracted and derivatized simultaneously on the Extrelut column. AP and MA were derivatized to the N-propoxycarbonyl derivatives using propylchloroformate. Pentadeuterated MA was used as an internal standard. The recoveries of AP and MA from urine were 88.2 and 92.5%, and those from blood were 89.7 and 90.3%, respectively. The calibration curves showed linearity in the range of 12.5-2000 ng/ml (ng/g) for AP and MA in urine and blood, and 0.25-20 ng/mg in hair. When urine samples containing two different concentrations (200 and 1000 ng/ml) of AP and MA, blood samples containing two different concentrations (200 and 1000 ng/g) of AP and MA, hair samples containing two different concentrations (0.5 and 5.0 ng/mg) of AP and MA, the coefficients of variation of intra-day and inter-day were 0.68-3.60% in urine, 0.42-4.58% in blood, and 1.20-13.1% in hair. Furthermore, this proposed method was applied to a medico-legal case of MA intoxication.