Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Pentachlorophenol”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,225 records · Page 68Linked to original sources
PubMed2000

Evaluation of solid substrates for enzyme production by Coriolus versicolor, for use in bioremediation of chlorophenols in aqueous effluents.

In the development of a system for the removal of chlorophenols from aqueous effluents, a range of solid substrates for the growth of Coriolus versicolor were investigated. Substrates included wood chips, cereal grain, wheat husk and wheat bran. Suitability for transformation of chlorophenols depended on laccase production by the fungus. The greatest amount of laccase (<25 Units g(-1) substrate) was produced on wheat husk and wheat bran over 30 days colonisation. Aqueous extracts of laccase from wheat husk and wheat bran cultures removed 100% of 2,4-dichlorophenol (50 ppm) from solution within 5 h and 75-80% of pentachlorophenol (50 ppm) within 24 h. Wheat bran was formulated into pellets with biscuit flour to provide a compact substrate for fungal immobilisation. Addition of 8-12% yeast extract to the pellets increased laccase production five-fold. Colonised pellets were added to chlorophenol solutions in 200-4000-ml bioreactors, resulting in >90% removal of chlorophenols within 100 min.

Basidiomycota↗
PubMed1997

Rapid method for detecting Desulfitobacterium frappieri strain PCP-1 in soil by the polymerase chain reaction.

A rapid method was developed for detecting in soil Desulfitobacterium frappieri strain PCP-1, an anaerobic gram-positive bacterium, isolated from a methanogenic consortium degrading pentachlorophenol. The method involved the establishment of a protocol for extracting total DNA from soil with the least contamination, and the use of the polymerase chain reaction (PCR) to detect strain PCP-1 with primers targeted with PCP-1 16S rRNA. To optimize the DNA extraction conditions, a glass mill homogenizer and a low-salt buffer containing polyvinylpolypyrrolidone were used on a black soil rich in organic matter. Recovered DNA was further purified with phenol/chloroform extractions, ammonium acetate precipitation and a G200 Sephadex gel-filtration column. DNA was extracted from soil supplemented with different concentrations of PCP-1 cells. Detection of PCP-1 was by PCR. The limit of detection was 800 added PCP-1 cells/g dry soil. This level of detection was achieved when the T4 gene-32 protein and 1 microgram soil DNA were added to the PCR mixture followed by a nested PCR. This method is quick, sensitive, and can process several samples at the same time.

Bacteria, Anaerobic↗
PubMed2002

Biological monitoring of metals and organic substances in hazardous-waste incineration workers.

OBJECTIVES: To determine blood and urine concentrations of a number of metals and organic substances in workers at a hazardous-waste incinerator (HWI) 1 year after regular operations in the facility, and to compare these concentrations with the baseline levels. METHODS: The employees were divided into three groups according to their workplaces. Plasma analyses of hexachlorobenzene (HCB), polychlorinated biphenyls (PCBs 28, 52, 101, 138, 153 and 180) and polychlorinated dibenzo- p-dioxins and dibenzofurans (PCDD/Fs), and urinary analyses of 2,4- and 2,5-dichlorophenol (DCP), 2,4,5- and 2,4,6-trichlorophenol (TCP), pentachlorophenol (PCP) and 1-hydroxypyrene (1-HP) were carried out. The blood concentrations of beryllium, manganese, mercury and lead, and the urine levels of cadmium, chromium, nickel and vanadium were also determined. RESULTS: The current plasma HCB, PCB and PCDD/F levels, and the urine levels of chlorophenols (CLPs) and 1-HP did not show significant differences between workplace groups or the baseline concentrations. Moreover, no significant differences between metal levels could be observed. DISCUSSION AND CONCLUSION: The lack of differences between the current levels of metals and organic substances and the respective baseline concentrations, together with the absence of differences depending on the workplace indicate that the potential exposure of HWI workers to the analyzed compounds was insignificant. According to these results, 1 year of potential exposure to the above metals and organic substances would not mean any specific health problem for the workers at the HWI.

Adult↗
PubMed2001

Levels of metals and organic substances in blood and urine of workers at a new hazardous waste incinerator.

OBJECTIVE: To assess baseline concentrations of a number of metals and organic compounds in blood and urine of 28 workers employed at a new hazardous waste incinerator (HWI), before operation of the plant. METHODS: Plasma analyses of hexachlorobenzene (HCB), polychlorinated biphenyls (PCB 28, 52, 101, 138, 153 and 180), benzene, toluene, ethylbenzene, m-xylene, and polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) were carried out. The urinary levels of 2,4- and 2,5-dichlorophenol (DCPs), 2,4,5- and 2,4,6-trichlorophenol (TCPs) and pentachlorophenol (PCP), as well as those of 1-hydroxypyrene (1-HP) were also measured. Beryllium (Be), manganese (Mn), mercury (Hg) and lead (Pb) concentrations were determined in total blood, while the levels of arsenic (As), cadmium (Cd), chromium (Cr), nickel (Ni) and vanadium (V) were measured in urine. RESULTS: The levels of benzene, toluene, ethylbenzene and m-xylene were under their respective detection limits. The concentrations of HCB, PCBs and PCDD/Fs in plasma of the HWI workers, chlorophenols (CLPs) and 1-HP urinary concentrations, as well as those of metals in blood and urine are shown. PCDD/F concentrations in plasma of the new HWI workers ranged between 13.4 and 84.0 pg international toxic equivalents (I-TEQ)/g lipid, with a geometric mean value of 24.4 pg I-TEQ/g lipid. DISCUSSION: PCDD/F levels, as well as the concentrations of PCBs were of the same order of magnitude as those recently obtained for non-occupationally exposed populations of Catalonia (Spain). No significant gender differences were found for the levels of HCB, PCBs and PCDD/Fs. Although the present results showed a notable variability in the levels of CLPs, geometric mean values of these compounds were similar or even lower than those considered as potential reference values. Metal concentrations in blood and urine were also of the same order of magnitude than previously reported metal levels in the same area. CONCLUSION: The present results should be useful in future surveys in which internal exposure of the HWI workers will be determined.

Adult↗
PubMed1997

Internal exposure to hazardous substances of persons from various continents: investigations on exposure to different organochlorine compounds.

UNLABELLED: The aim of the study was to investigate the concentration of organochlorine compounds of environmental-medical relevance in biological materials from refugees with regard to their countries of origin and to compare these concentrations with the internal exposure of the German general population. METHODS: During medical examination after entry to Germany specimens could be taken from the refugees to determine the following parameters of biological monitoring: 1,1-dichloro-2,2-bis(-chlorophenyl)-ethylene (DDE-P), polychlorinated biphenyls (PCB-P), pentachlorophenol (PCP-P) and the beta- and gamma-hexachlorocyclohexanes (beta-HCH-P, gamma-HCH-P) in plasma and the excretion of chlorophenols (4-MCP-U, 2,4-DCP-U, 2,5-DCP-U, 2,4,5-TCP-U, 2,4,6-TCP-U, 2,3,4,5-TeCP-U, 2,3,5,6-TeCP-U) in urine. One hundred and three men (13 from former Yugoslavia, 29 from the former USSR, 33 Africans and 28 Asians) ranging from 16 to 53 years of age (median 27 years) were investigated. Thirty four male Germans without occupational exposure to these substances and a similar age structure (age 25-36 years; median 26 years) served as a control group. RESULTS: A much higher level of internal exposure was found for the DDT metabolite, DDE, for those persons from Asia, the former USSR and Africa compared with the German controls (medians: 16.9 micrograms/l, 11.9 micrograms/l and 10.9 micrograms/l) and 1.1 micrograms/l). The levels of PCB in plasma were below the detection limit in the majority of refugees. In the control group, however, the PCB levels were higher (sigma PCB; median: 2.1 micrograms/l, maximum: 13.3 micrograms/l). The highest beta-HCH concentrations, up to a maximum of 15.5 micrograms/l, were detected in the persons from the former USSR and Asia. The five groups do not differ with regard to internal exposure to PCP and gamma-HCH. Renal excretion of 4-MCP, 2,4-DCP and TeCP did not differ between the five groups. The concentrations of 2,5-DCP in urine, however, were significantly lower in the Germans than the refugees from the four regions investigated. The median for the Germans was 3.0 micrograms/l and for the refugees between 10.8 and 14.7 micrograms/l. Also the levels of 2,4,5-TCP and 2,4,6-TCP in urine were lower in the German controls than in the men from the former USSR, Africa and Asia. CONCLUSIONS: Organochlorine compounds exist worldwide due to their extensive use. There are, however, regional differences for the various substance groups, which during biological monitoring are seen in the different background exposures of the general population. Particularly characteristic are markedly higher levels of DDE in plasma from the refugees compared with the German population.

Adolescent↗
PubMed1999

Reference values and human biological monitoring values for environmental toxins. Report on the work and recommendations of the Commission on Human Biological Monitoring of the German Federal Environmental Agency.

This article describes the working principles and working procedures of the Commission on Human Biological Monitoring, which was established in 1993 as a joint commission of the Federal Health Office (Bundesgesundheitsamt) and the Federal Environmental Agency (Umweltbundesamt) in Germany. One of the main tasks of the commission is to develop scientifically based criteria for the application of human biological monitoring and for the evaluation of human monitoring data in environmental medicine. In principle, two different kinds of criteria are recommended: (a) reference values and (b) human biological monitoring values (HBM values). Reference values are intended to indicate the upper margin of the current background exposure of the general population to a given environmental toxin at a given time. Reference values can be used to identify subjects with an increased level of exposure (in relation to background exposure) to a given environmental toxin. However, reference values do not represent health-related criteria for the evaluation of human biological monitoring data. HBM values are derived from human toxicology and epidemiology studies and are intended to be used as a basis for a health-related evaluation of human biological monitoring data. Usually the commission recommends two different HBM values: HBM I, the concentration of an environmental toxin in a human biological material (usually blood, serum, plasma, or urine) below which there is--according to the knowledge and judgement of the commission--no risk for adverse health effects in individuals of the general population: and HBM II, the concentration of an environmental toxin in a human biological material (usually blood, serum, plasma, or urine) above which there is--according to the knowledge and judgement of the commission and with regard to the environmental toxin under consideration--an increased risk for adverse health effects in susceptible individuals of the general population. The HBM I value can be considered a kind of alert value (from the toxicological point of view), whereas the HBM II value represents a kind of action level, at which attempts should be undertaken to reduce the level of exposure immediately and to carry out further medical examinations. Values between HBM I and HBM II should be considered a warning signal of the need to control the analytical measurement and to reduce the level of exposure of the concerned individual as reasonably as is achievable. At present, reference and HBM values are available for lead in blood, for cadmium and mercury in blood and urine, and for pentachlorophenol in plasma/serum and urine. Reference values have been established for some polychlorinated biphenyls in blood and plasma as well as for hexachlorocyclohexane and hexacholorobenzene in blood as well as for some organochlorine in human milk.

Adolescent↗
PubMed2003

Combination ecotoxicity and testing of common chemical discharges to sewer using the Vibrio fischeri luminescence bioassay.

In order to investigate possible synergistic or antagonistic (more or less than additive) toxicity effects, mixtures of chemicals were tested in water using a microbial bioassay. Ten toxicants (3,4-dichloroaniline, 3,5-dichlorophenol, cadmium, chromium, copper, Lindane, linear alkylbenzene sulphonate, pentachlorophenol, toluene, zinc) were chosen on the basis of their common occurrence in industrial effluents within local waste water treatment plants. These toxicants also cover a wide range of modes of toxic action, namely, polar and non-polar narcosis, membrane disruption, respiratory disruption, uncouplers of oxidative phosphorylation, biochemical disruption and enzyme inhibition. Efficient screening for possible combination toxicity between toxicants involved testing the chemicals both singly and in triplet combinations. The triplets were based on four replicates of a balanced incomplete block design (BIB). A standardised Vibrio fischeri rapid toxicity bioluminescence assay was used. The combinations tested showed that only one mixture was found to be significantly more toxic than expected from the pure single-toxicant results. Two triplets were significantly less toxic. Further tests on the more toxic triplet showed that the effect was due to only one of the 45 pairs originally screened. It is concluded that synergistic effects in combinations of toxicants are rather rare in bioluminescence systems utilising common effluents discharged to sewer.

Biological Assay↗
PubMed1985

Metabolic activation of mutagenic N-hydroxyarylamines by O-acetyltransferase in Salmonella typhimurium TA98.

A new enzymatic activation of mutagenic N-hydroxyarylamines is described. An acetyl-CoA dependent enzyme that can activate 2-hydroxyamino-6-methyldipyrido[1,2-a:3',2'-d]imidazole (N-OH-Glu-P-1) to a reactive species capable of binding to nucleic acid was found in a cell-free extract of Salmonella typhimurium TA98 but not in that of TA98/1,8-DNP6, which shows low sensitivity to the mutagenic activity of N-OH-Glu-P-1. The enzyme was partially purified by streptomycin treatment, ammonium sulfate precipitation, DEAE-cellulose chromatography, and gel filtration chromatography of Sephadex G-150. Its molecular weight was estimated to be approximately 48,000. The directly mutagenic N-hydroxyarylamines, such as N-OH-Glu-P-1, 3-hydroxyamino-1-methyl-5H-pyrido[4,3-b]indole (N-OH-Trp-P-2), and N-hydroxy-2-aminofluorene (N-OH-AF), were transformed to reactive derivatives by partially purified enzyme in the presence of acetyl-CoA. The Km value for acetyl-CoA was calculated to be 3.3 microM. No acetyl residue, however, was incorporated into nucleic acid adducts. The enzymatic product of N-OH-Glu-P-1 bound most efficiently to polyguanylic acid among four polynucleotides. The enzyme did not show the N,O-acetyltransfer activity of N-hydroxyacetylaminofluorene (N-OH-AAF). These results indicate that the enzymatic product of N-hydroxyarylamine is N-acetoxyarylamine, and that this enzyme can be called acetyl-CoA:N-hydroxyarylamine O-acetyltransferase. O-Acetyltransferase activity was inhibited by SH-blocking agents, several phenolic compounds, such as pentachlorophenol and 1-nitro-2-naphthol, and an antibiotic thiolactomycin. S. typhimurium mutation studies suggested that the O-acetyltransferase functions as an enzyme activating certain N-hydroxyarylamines within bacterial cells and is involved in the formation of mutants.

Acetyltransferases↗
PubMed1975

Stepwise reduction of cytochromes b-562, b-566 and b-558 in rat liver mitochondria.

1. Addition of KCN to aerobic, rotenone-inhibited rat liver mitochondria with out addition of substrate caused reduction of cytochromes b-562 (having an alpha-band at 562 nm at room temperature), c + c1, and a + a3. The effect of KCN on cytochrome b-562 was reversed by pentachlorophenol, though the effect of KCN on cytochromes c+c1 and a+a3 was not reversed by this uncoupler.2. Addition of ATP to aerobic, rat liver mitochondria inhibited with 500 muM KCN under conditions were cytochromes b-562, c+c1 and a+a3 were reduced, caused reduction of cytochrome b-566. The absorbance spectrum of cytochrome b-566 had an alpha-band at 565.5 nm, a beta-band at 538 nm and a gamma-band at 431 nm, but no shoulder around 558 nm at room temperature. 3. Addition of succinate to rotenone-KCN-inhibited and ATP-treated rat liver mitochondria under conditions where cytochromes b-566, b-562, c+c1 and a+a3 were already fully reduced, caused reduction of cytochrome b-558 (having an alpha-band at 558 nm, a beta-band at 527 nm and a gamma-band at 426 nm at room temperature) after exhaustion of molecular oxygen in the reaction medium, without any contribution from a long-wavelength species (cytochrome b-566). 4. It was concluded that the 558-nm band is not a short-wavelength shoulder of cytochrome b-566, but is due to a different species from cytochrome b-566.

Adenosine Triphosphate↗
PubMed1980

Kinetics of L-[14C]leucine transport in Saccharomyces cerevisiae: effect of energy coupling inhibitors.

1. L-[14C]Leucine transport into Saccharomyces cerevisiae involves a high-affinity, low-velocity system (system 1) and a low-affinity, high-velocity system (system 2). These systems are characterized by the different values of the kinetic parameters KT and Jmax, and are both capable of concentrative transport. The general amino acid permease is assumed to be a part of the high-affinity system. 2. The kinetics of L-[14C]leucine entrance show and initial rapid phase (the 'very early uptake') before reaching the steady-state rate. The contribution of the very early uptake to total entrance values affects the values of KT and Jmax, especially when the steady-state rate is relatively slow, as with starved yeast, and then negative KT and Jmax values may result. The very early uptake is increased by pretreatment of starved yeast and D-glucose, this latter effect being counteracted by iodoacetate. 3. After energization of starved yeast by pretreatment with D-glucose or propionaldehyde, the apparent KT,2 value greatly decreases whilst the KT,1 value decreases to a much more limited extent, or does not vary. With the energized yeast, KT,2 decreases throughout incubation whilst KT,1 variation is insignificant. Energization increases Jmax,1 and Jmax,2 several-fold and with the energized yeast at the steady-state phase, Jmax,2 greater than or equal to 4Jmax,1. Variation of KT and Jmax values as a function of the metabolic state of yeast cells may be explained in terms of variation of rate constants k-1, k+1 and k+2 for each transport system. 4. Dicyclohexylcarbodiimide, quercetin and diethylstilbestrol inhibit tranport at 0.05 mM L-[14C]leucine, in good agreement with a function of the plasmalemma ATPase for the operation of system 1. Dio-9, propionic and isobutyric acids, pentachlorophenol, carbonylcyanide 3-chlorophenylhydrazone and carbonylcyanide 4-trifluoromethoxyphenylhydrazone, which affect the proton gradient and/or the membrane potential inhibit L-[14C]leucine uptake at all the assayed amino acid concentrations. 5. The polyene antibiotic, nystatin, which forms channels in membranes permeable to K+ and H+, inhibits systems 1 and 2 activity but enniatin (also a K+ ionophore) does not.

Anti-Bacterial Agents↗
PubMed1988

The comparative influence of substituted phenols (especially chlorophenols) on yeast cells assayed by electro-rotation and other methods.

The toxicity of 31 phenols was studied by electro-rotation of yeast cells. Control yeast cells show both anti-field and co-field rotation, depending upon the field frequency applied. After treatment with supra-threshold amounts of phenols the anti-field rotation is weakened or abolished and a stronger co-field rotation can be seen. The proportion of cells showing the co-field rotation was found to be a sensitive measure of toxicity. Doses of 2.2 mumol/l of pentachlorophenol, or of 0.3 mumol/l of pentabromophenol were detectable after 3 h incubation at pH 4.0. At a given pH, the toxicity of the chlorophenols correlated extremely well with their octanol:water partition coefficients (Pow). The complete set of phenols showed fair overall correlation with Pow, but less good correlation with their acidity constants (pKa). In particular the toxicity of a given phenol was less than predicted from its pKa if the incubation pH was higher than the pKa. Biochemical assays on 23 of the phenols showed that the rotational sensitivity runs closely parallel to the sensitivities of cell growth rate and of the plasmamembrane ATPase, but less closely to the inhibition of purine incorporation. It appears that the electro-rotation method provides a useful and rapid test for the presence of organic ecotoxins. The test enables us to distinguish differences between single cells, and is comparable in sensitivity to biochemical tests that use vesicles or homogenates derived from a cell population.

Acids↗
PubMed1983

Ultimate forms of mutagenic and carcinogenic heterocyclic amines produced by pyrolysis.

A mutant strain of Salmonella typhimurium TA98/1,8-DNP6 isolated by McCoy et al. (1) was reported to be defective in esterifying activity. We have found that 2-amino-6-methyldipyrido[1,2-a:3',2'-d]imidazole (Glu-P-1), 2-aminodipyrido[1,2-a:3',2'-d]imidazole (Glu-P-2), 2-amino-3-methylimidazo-[4,5-f]quinoline (IQ), 2-amino-3,4-dimethylimidazo[4,5-f]quinoline (MeIQ) and 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx) were not mutagenic to TA98/1,8-DNP6 with S9 mix, while these compounds were strongly mutagenic to the original TA98 with S9 mix. The mutagenicities of some of these heterocyclic amines to TA98 were inhibited by pentachlorophenol, an aryl sulfotransferase inhibitor. These results indicate that the ultimate forms of these heterocyclic amines are probably sulfate esters of heterocyclic amine N-hydroxides. Contrary to this, 3-amino-1,4-dimethyl-5H-pyrido[4,3-b]indole (Trp-P-1), 3-amino-1-methyl-5H-pyrido[4,3-b]indole (Trp-P-2), 2-amino-9H-pyrido[2,3-b]indole (A alpha C) and 2-amino-3-methyl-9H-pyrido[2,3-b]indole (MeA alpha C) were definitely mutagenic to TA98/1,8-DNP6, although less than to TA98.

Amines↗
PubMed1984

Structural and functional properties of rat liver mitochondria in hexachlorobenzene induced experimental porphyria.

A possible link between changes in iron and porphyrin content in liver mitochondria, from rats treated with either hexachlorobenzene, iron, or hexachlorobenzene plus iron, as a function of treatment time and their structural-functional properties, has been investigated. Normal oxidative phosphorylation in mitochondria from rats treated with iron has been shown. By contrast a significant and constant uncoupling of the phosphorylative process, fully reversed by albumin, in mitochondria from rats treated with hexachlorobenzene and hexachlorobenzene plus iron has been presented. A possible involvement of pentachlorophenol in causing these abnormalities has been proposed.

Animals↗
PubMed1989

The metabolism of pentachlorobenzene by rat liver microsomes: the nature of the reactive intermediates formed.

Metabolism of [14C]-pentachlorobenzene by liver microsomes from dexamethasone-induced rats results in the formation of pentachlorophenol and 2,3,4,6-tetrachlorophenol as major primary metabolites in a ratio of 4:1, with 2,3,4,5- and 2,3,5,6-tetrachlorophenols as minor metabolites. The unsubstituted carbon atom is thus the favourite site of oxidative attack, but the chlorine substituted positions still play a sizable role. As secondary metabolites both para- and ortho-tetrachlorohydroquinone are formed (1.4 and 0.9% of total metabolites respectively). During this cytochrome P450-dependent conversion of pentachlorobenzene, 5-15% of the total amount of metabolites becomes covalently bound to microsomal protein. Ascorbic acid inhibits this binding to a considerable extent, indicating that quinone metabolites play an important role in the binding. However, complete inhibition was never reached by ascorbic acid, nor by glutathione, suggesting that other reactive intermediates, presumably epoxides, are also responsible for covalent binding.

Animals↗
PubMed1982

Multiple forms of phenolsulphotransferase in human tissues: selective inhibition by dichloronitrophenol.

Evidence is presented for two functional forms of phenolsulphotransferase in human tissues: (1) activity ratios, using dopamine and phenol as substrates, varied 30-fold between different tissues, whereas the dopamine to tyramine activity ratio was relatively constant; (2) incubation at 37 degrees caused a selective decrease in activity towards dopamine compared with phenol; and (3) phenol sulphoconjugation was selectively inhibited by dichloronitrophenol and pentachlorophenol compared with that of dopamine and tyramine. The two forms, which have been designated M (monoamines) and P (phenol), were both present in platelets, jejunum, adrenal and brain.

Arylsulfotransferase↗
PubMed1984

Enzymatic sulfation of steroids--XX. Effects of ten drugs on the hepatic glucocorticoid sulfotransferase activity of rats in vitro and in vivo.

The effects of ten drugs on hepatic glucocorticoid sulfotransferase activity (HGSTA) were examined in male rats. The enzyme activity per 100 g body weight was elevated 152, 94.9, 140, 140, 73.1, 63.9, 76.9, and 140% after administration of daily i.p. doses of 111 mg spironolactone/kg (6-10 days), 66.7 mg WIN-24540/kg (6-10 days), 150 mg metyrapone/kg (19-31 days), 33.3 mg pentachlorophenol/kg (9-16 days), 16.5 mg aspirin/kg (10-16 days), 90.5 mg alloxan/kg (23.27 days), 104 mg aminoglutethimide/kg (12-20 days), and 16.8 mg propranolol/kg (21-27 days). Shorter experimental periods or lower drug doses caused smaller effects on HGSTA. Most notably, spironolactone (111 mg/kg) and WIN-24540 (66.7 mg/kg) caused 50-75% elevation of HGSTA in 2 days. Effects of WIN-24540, aspirin and pentachlorophenol were due mostly to elevation of hepatic levels of sulfotransferase III (STIII), the glucocorticoid-preferring sulfotransferase of rat liver. Effects of the other test drugs were due to elevation of hepatic levels of sulfotransferases I and II (STI and STII), which much prefer dehydroepiandrosterone as substrate, but also catalyze glucocorticoid sulfation. Enzyme inhibition studies showed that the test drugs interacted with the HGSTA in vitro in a fashion that appeared to be related to the in vivo effects already described. None of the drugs interacted exclusively with STI, STII or STIII in vitro. However, some differences of the strengths of individual drug-sulfotransferase interactions were observed. The drug effects are discussed in relation to drug and glucocorticoid actions.

Animals↗
PubMed1988

Activity of the anion exchange protein (band 3) of human erythrocytes as affected by hydroxychloroaromatic chemicals.

The membranous segment of the anion transport protein (band 3) of the human erythrocyte membrane has been shown [T.L. Miller and R.J. Smith, Archs Biochem. Biophys. 250, 128 (1986)] to be destabilized by relatively low concentrations of many hydroxychloroaromatic compounds (HO-Cl chi-Ar), including hydroxychlorodiphenyl ethers (HO-Cl chi-DPE), major contaminants of technical grade pentachlorophenol (PCP). In the present study, HO-Cl chi-DPE also caused a concentration-dependent inhibition of the rate of sulfate exchange mediated by band 3 in human erythrocytes. The most active compound studied, 2-HO-Cl9-DPE, was about nine times more potent in inhibiting sulfate exchange than 2-HO-2',4,4'-Cl3-DPE, the least active compound studied. The potency of HO-Cl chi-DPE as inhibitors of anion exchange generally increased with the degree of chlorination. The concentration-dependent decreases in the sulfate exchange rate elicited by 2-HO-Cl9-DPE and 2-HO-2',4,4'-Cl3-DPE paralleled the effects of these compounds on the stability of band 3.

Anion Exchange Protein 1, Erythrocyte↗
PubMed1989

Sulphotransferase-mediated activation of the carcinogen 5-hydroxymethyl-chrysene. Species and sex differences in tissue distribution of the enzyme activity and a possible participation of hydroxysteroid sulphotransferases.

Sulphation of the carcinogen 5-hydroxymethyl-chrysene (5-HCR) to the active metabolite 5-HCR sulphate occurred at significant rates in all of hepatic cytosols prepared from the male and female experimental animals, rats, mice, guinea-pigs and hamsters. The 5-HCR-sulphating activity was also found in kidney cytosols of all the experimental animals used, while their activities were much less than those of hepatic cytosols. In the male mice, the enzyme activity of testis was higher than any other examined tissue. Small intestine and adrenal of male and female guinea-pigs had relatively high enzyme activities. Small enzyme activities were also found in a variety of extrahepatic tissues of some of these animals. Marked species and sex differences (female much greater than male in the rat and mouse) were observed in the hepatic enzyme activity. In the female rat liver which showed the highest 5-HCR-sulphating activity among the examined tissues of all the animals, a typical hydroxysteroid sulphotransferase inhibitor, dehydroepiandrosterone (DHA) sulphate (1 mM), potently and competitively inhibited the sulphation of 5-HCR as well as that of DHA, a typical substrate for hydroxysteroid sulphotransferases. On the contrary, the phenol sulphotransferase inhibitors, pentachlorophenol and 2,6-dichloro-4-nitrophenol, had only a little effect on these enzyme activities even at a concentration of 50 microM that showed a potent inhibition of the phenol sulphotransferase activity. These results suggest that 5-HCR be sulphated in the female rat liver by hydroxysteroid sulphotransferases, but not by phenol sulphotransferases.

Animals↗