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Effects of nonylphenol, 1,1-dichloro-2,2-bis(p-chlorophenyl)ethylene (p,p'-DDE), and pentachlorophenol on the adult female guinea pig reproductive tract.

The guinea pig exhibits cyclic and luteal similarities to the human, a feature not present in other small experimental animals such as rats, mice, or rabbits. Studies were undertaken to investigate the in vivo effects of three persistent environmental xenobiotics (nonylphenol, 1,1-dichloro-2,2-bis(p-chlorophenyl)ethylene [p,p'-DDE], and pentachlorophenol) on the microanatomy of the adult female guinea pig reproductive system. The effects brought about by these compounds (40 mg/kg/day) were compared to those caused by the synthetic estrogen diethylstilbestrol (DES; 50 microg/kg/day). Adult female guinea pigs, intact and castrated, were treated with 14 daily subcutaneous (s.c.) doses of one of these agents. The 50% decline in the weight of the tract that occurred following castration, was prevented by administration of nonylphenol, p,p'-DDE, and DES, but not of pentachlorophenol. Nonylphenol produced weak estrogenic stimulation of the tract of intact animals and maintained a relatively normal histologic appearance in castrated animals. Focal mucinous metaplasia of the endometrium, however, was observed in both groups. Treatment of intact and castrated animals with p,p'-DDE resulted in cystic hyperplasia and mucinous metaplasia of the endometrium, hyperplasia of the cervical epithelium, estrogenic stimulation of the vagina, and dilation of the rete ovarii. Treatment of intact or castrated animals with DES resulted in effects that were qualitatively similar to those caused by p,p'-DDE. The appearance of the vaginal epithelium, however, was abnormal and the rete ovarii were less dilated. Pentachlorophenol had minimal effect on the histology of the tract of castrated or intact animals. These data support our hypothesis that some environmental toxicants can substitute for estradiol in regulating the microanatomy of the female reproductive tract. They indicate the potential of these compounds to act as endocrine disrupting agents.

Animals↗

Liquid chromatographic determination of pentachlorophenol in serum, using pre-column phase-transfer catalysed dansylation and post-column photolysis with fluorescence detection.

Dansylation of pentachlorophenol was carried out after solid-phase extraction of acidified human serum and desorption with dichloromethane, in a dichloromethane-water two-phase system using tetrabutyl-ammonium bromide as the phase-transfer catalyst. Derivatisation was complete within 2 min at room temperature. After evaporation of an aliquot of the organic phase, the residue was dissolved in methanol and injected into a reversed-phase chromatographic system, equipped with a post-column photochemical reactor. In the reactor, dansylated pentachlorophenol is converted into highly fluorescent products. The recovery of the analyte from serum was 85 +/- 4%. Calibration graphs for horse and human serum were linear over two decades, with correlation coefficients ranging from 0.996 to 0.999. The detection limit of pentachlorophenol in horse and human serum was 400 pg ml-1. The reproducibility of the total procedure for a human serum sample containing 4 ng ml-1 was 4.5%.

Catalysis↗

Inhibition of bacterial transport by uncouplers of oxidative phosphorylation. Effects of pentachlorophenol and analogues in Bacillus subtilis.

Analogues of the potent uncoupler of oxidative phosphorylation pentachlorophenol were tested as inhibitors of proline and glycine transport by Bacillus subtilis. These analogues included less highly substituted chlorophenols and pentachlorothiophenol. Like pentachlorophenol, they are non-competitive inhibitors of proline transport and uncompetitive inhibitors of glycine transport. However, the less highly substituted chlorophenols are weaker acids than pentachlorophenol and also weaker inhibitors. Analysis indicated that the anionic form of the uncouplers is the inhibiting species. Pentachlorothiophenol, a water-insoluble anion, is also a potent inhibitor. These results support previous studies that concluded that uncouplers of oxidative phosphorylation inhibit amino acid transport by binding at specific sites on proteins, the free energy of interaction stabilizing 'unproductive' conformations. Such specific interactions of uncoupler with protein are probably commonplace.

Bacillus subtilis↗

Effects of the pesticides carbofuran, chlorpyrifos, dimethoate, lindane, triallate, trifluralin, 2,4-D, and pentachlorophenol on the metabolic endocrine and reproductive endocrine system in ewes.

Many pesticides are used in the agricultural environment, and some may have the potential to disrupt reproductive or endocrine function. Ewes, in separate groups of 6, received orally into their rumen either empty gelatin capsules or capsules containing chlorpyrifos (12.5 mg/kg), trifluralin (17.5 mg/kg), lindane (2.5 mg/kg), or pentachlorophenol (2 mg/kg) 2 times per week for 43 d. Dimethoate (0.2 mg/kg), carbofuran (0.30 mg/kg), 2,4-dichlorophenoxyacetic acid (10 mg/kg), or triallate (5 mg/kg) was given 3 times per week. After 36 d of treatment, blood samples were taken every 12 min for 6 h for hormone analysis. Ewes were euthanized at the end of the study for necropsy and histopathology. No overt signs of toxicity were seen, and body weight was not affected by treatment. Carbofuran caused a significant increase in serum concentrations of thyroxine compared to control ewes, but all other pesticides, except trifluralin, resulted in a marked decrease in thyroxine concentrations. Serum concentrations of cortisol were significantly increased by trifluralin and chlorpyrifos. Concentrations of insulin in serum were markedly increased in ewes given dimethoate, lindane, trifluralin, triallate, and pentachlorophenol, and concentrations of estradiol were also significantly increased in ewes given lindane and trifluralin. Mean serum concentrations of LH were markedly decreased by trifluralin, and basal LH concentrations were significantly decreased by lindane, dimethoate, and trifluralin but increased by triallate. Both pentachlorophenol and triallate caused a significant increase in severity of oviductal intraepithelial cysts in ewes. Data suggest that several currently used pesticides could influence serum concentrations of reproductive and metabolic hormones, particularly thyroxine, the major secretory product of the thyroid and a principal regulator of metabolism.

Agriculture↗

Levels of polychlorinated dibenzo-p-dioxins and dibenzofurans in cattle raised at agricultural research facilities across the USA and the influence of pentachlorophenol-treated wood.

Adipose tissue samples from 158 cattle raised locally at experiment stations across the USA were analysed for polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/F). While 80% of the samples had PCDD/F concentrations that fell within the range of a previous US survey of beef animals (not detected -4.1 ppt toxic equivalency), several animals had exceptionally high concentrations (8-54 ppt toxic equivalency). The investigations of three facilities where highly contaminated animals were raised found pentachlorophenol-treated wood at each site. The congener pattern in the animals' tissues and the lack of elevated PCDD/F levels in other environmental samples, i.e. hay and soil, indicated that the treated wood was the source of contamination. A congener pattern similar to that of pentachlorophenol-exposed animals was seen for the means and medians of the entire data, i.e. OCDD, HpCDD and 1,2,3,6,7,8-HxCDD dominated, the PCDD concentrations equalled or exceeded the furan concentrations, and the concentration of 1,2,3,6,7,8-HxCDD was six times that of the other HxCDD isomers. This suggested that pentachlorophenol-treated wood contributed measurably to many of the animals in this survey. The largest contributors to the median toxic equivalencies were 1,2,3,7,8-PeCDD (40%) and 1,2,3,6,7,8-HxCDD (16%). No clear geographical trends emerged from the data.

Adipose Tissue↗

The initiation of gamma-glutamyltranspeptidase positive foci in the rat liver by N-hydroxy-2-acetylaminofluorene. The effect of the sulfation inhibitor pentachlorophenol.

The role of sulfation of the carcinogen N-hydroxy-2-acetyl-aminofluorene in the initiation phase of liver-tumor formation was studied in an initiation-promotion model modified from the Solt and Farber system (Cancer Res., 43, 188-191, 1983). The effect of the sulfation inhibitor pentachlorophenol on the induction by N-hydroxy-2-acetylaminofluorene of gamma-glutamyltranspeptidase positive foci of cells (regarded as a population of cells from which neoplastic cells will develop) was determined. Inhibition of sulfation did not prevent the induction of gamma-glutamyltranspeptidase positive foci in rat liver; on the contrary, an increase was observed. Since it is known that inhibition of sulfation of N-hydroxy-2-acetylaminofluorene prevents the formation of covalently-bound 2-acetylaminofluorene adducts to proteins, RNA, and DNA in the rat liver (Meerman et al., Carcinogenesis, 2, 413-416, 1981), the results from this study suggest that deacetylated, 2-aminofluorene adducts to DNA are responsible for initiation of gamma-glutamyltranspeptidase positive foci in the rat liver (because formation of these adducts is not affected by pentachlorophenol). After initiation with a single dose of N-hydroxy-2-acetylaminofluorene, proliferation of 'oval cells' was observed only 1 week after administration of the carcinogen. This was not observed in the livers of rats pre-treated with pentachlorophenol in which the largest number of foci develops. These data therefore suggest that 'oval cells' are not involved in the development of gamma-glutamyltranspeptidase positive foci.

2-Acetylaminofluorene↗

Kinetics of microbial growth on pentachlorophenol.

Batch and fed-batch experiments were conducted to examine the kinetics of pentachlorophenol utilization by an enrichment culture of pentachlorophenol-degrading bacteria. The Haldane modification of the Monod equation was found to describe the relationship between the specific growth rate and substrate concentration. Analysis of the kinetic parameters indicated that the maximum specific growth rate and yield coefficients are low, with values of 0.074 h-1 and 0.136 g/g, respectively. The Monod constant (Ks) was estimated to be 60 micrograms/liter, indicating a high affinity of the microorganisms for the substrate. However, high concentrations (KI = 1,375 micrograms/liter) were shown to be inhibitory for metabolism and growth. These kinetic parameters can be used to define the optimal conditions for the removal of pentachlorophenol in biological treatment systems.

Bacteria↗

Effects of pentachlorophenol and some of its known and possible metabolites on different species of bacteria.

The antibacterial activity of pentachlorophenol and 35 of its known or possible metabolites against 30 different species of bacteria was tested. In comparison with pentachlorophenol, no increase of inhibitory activity was found for any of the chlorinated anisoles tested (except for pentachloroanisole against Streptomyces spp.), 2-chlorophenol, 2,6-dichlorophenol, 2,3,6- and 2,4,6-trichlorophenol, 2,3,5,6-tetrachlorophenol, tetrachloro-1,4- and -1,3-benzenediol (except for the 1,3-isomer against Streptomyces spp.), tetrachloro-1,3-dimethoxybenzene, and tetrachloro-1,3-benzenediol diacetate. Two chlorophenols, five dichlorophenols, four trichlorophenols, two tetrachlorophenols, and tetrachloro-1,2-benzenediol were more active than pentachlorophenol against some, but not all, of the strains tested.

Bacteria↗

Prolonged swimming, recovery and repeat swimming performance of mature sockeye salmon Oncorhynchus nerka exposed to moderate hypoxia and pentachlorophenol.

Mature, wild sockeye salmon (Oncorhynchus nerka) demonstrated their remarkable stamina and recovery abilities by performing three consecutive critical swimming speed tests with only a 45 min interval for recovery between subsequent tests. Although the repeated swimming challenges were performed without a full recovery, normoxic fish swam just as well on the second swim, and the majority of fish swam only marginally more poorly on the third swim. In addition, metabolic loading in these fish, as measured by the rate of oxygen consumption, ventilation rate and plasma lactate levels during recovery, did not appear to be cumulative with successive swims. Fish, however, did not recover as well after a similar level of initial swimming performance under moderately hypoxic conditions (water PO2>100 mmHg; 1 mmHg=0.1333 kPa). Four out of the five fish did not swim again and their high plasma lactate levels indicated a greater anaerobic effort. In another group of fish, metabolic loading (elevated control rates of oxygen consumption) was induced with an overnight sublethal exposure to pentachlorophenol, but these fish swam as well as normoxic fish on the first swim, and five of the six fish swam for a third time at a marginally lower critical swimming speed. In contrast to expectations, pentachlorophenol pretreatment and moderate hypoxia were not additive in their effects. Instead, the effects resembled those of pentachlorophenol pretreatment alone. The results are discussed in terms of what aspects of fatigue might impair the repeat swimming performance of sockeye salmon.

Animals↗

Significance of anion exchange in pentachlorophenol sorption by variable-charge soils.

Sorption data and subsequent predictive models for evaluating acidic pesticide behavior on variable-charge soils are needed to improve pesticide management and environmental stewardship. Previous work demonstrated that sorption of pentachlorophenol (PCP), a model organic acid, was adequately modeled by accounting for pH-and pKa-dependent chemical speciation and using two organic carbon-normalized sorption coefficients; one each for the neutral and anionic species. Such models do not account for organic anion interaction to positively charged surface sites, which can be significant for variable-charge minerals present in weathered soils typical of tropical and subtropical regions. The role of anion exchange in sorption of ionizable chemicals by variable-charge soils was assessed by measuring sorption of PCP by several variable-charge soils from aqueous solutions of CaCl2, CaSO4, Ca(H2PO4)2 as a function of pH. Differences in sorption from phosphate and chloride electrolyte solutions were attributed to pentachlorophenolate interactions with anion exchange sites. Suppression of PCP sorption by phosphate ranged from negligible in a soil with essentially no positively charge sites, as measured by negligible anion exchange capacity, to as much as 69% for variable-charge soils. Pentachlorophenolate exchange correlated well with the ratio of pH-dependent anion exchange capacity to net surface charge. Sorption reversibility of PCP by both CaCl2 and Ca(H2PO4)2 solutions was also demonstrated. Results for PCP clearly demonstrate that sorption to anion exchange sites in variable-charge soils should be considered in assessing pesticide mobility and that phosphate fertilizer application may increase the mobility of acidic pesticides.

Anions↗

[Detection of pentachlorophenol in natural rubber latex].

The method of detection of pentachlorophenol in natural rubber latex is proposed. Pentachlorophenol is isolated from other nonrubber-like substances by thin-layer chromatography and identified by spectroscopic method in UV-light. Isolation of pentachlorophenol is carried out from water extracts obtained from the dry caoutchouc films, so the same method can be used for examination of the rubber articles designed for the medicinetoo.

Chlorophenols↗

[Determination of pentachlorophenol residues in textiles and leather and leather products by gas chromatography/mass spectrometry].

A method for determination of pentachlorophenol residues in textiles and leather and leather products by gas chromatography/mass spectrometry was developed. The pentachlorophenol residues in samples was acidified with sulphuric acid solution (6 mol/L) and extracted with n-hexane. After the n-hexane layer was washed with sodium sulphate solution (20 g/L)until it was clear, determination was made by means of a gas chromatograph equipped with MSD, using external standard method. A DB-17 fused silica capillary column (30 m x 0.25 mm i.d.; 0.25 micron film thickness) was employed in the analysis, The column temperature program included a 2 min isothermal period at 50 degrees C, temperature increased at a rate of 30 degrees C/min to 220 degrees C, and hold for 1 min; temperature increased of at a rate 6 degrees C/min to 260 degrees C, and hold for 1 min. Mass spectra were obtained by electron impact at 70 eV and the determination was made by means of SIM mode, selected monitoring ion (m/z) was 264 amu. The detection limit was 0.02 mg/kg. The average recovery was from 86.7% to 93.1% and CV (n = 10) is from 4.1% to 5.9%. This method was already used to determine the mass concentration of pentachlorophenol residues in raw cotton, towel, shirt, leather gloves, leather watchguard. The method is simple, rapid and accurate.

Environmental Pollutants↗

[Pentachlorophenol concentrations in the organs and blood of 11 dead infants].

For 11 children, died on age between 2.5 and 57 month due to different causes, the concentrations of pentachlorophenol in liver, kidney, brain and blood were located in the lower part of the spread of test values found for adults which had died in the same region and during the same time phase. The concentrations of pentachlorophenol in the blood of the 11 children were compared further with the findings from 20 living children with an age up to 10 years and were all located below the median of the test values (45,4 micrograms PCP/1) from the group last mentioned. There are no hints for connections between the body-burden of pentachlorophenol and the death-cases concerning the 11 children.

Brain Chemistry↗

Neurochemical effects of peroral administration of technical pentachlorophenol.

Administration of technical pentachlorophenol in drinking water (20 mg/l) to male Wistar rats caused significant liver concentration of tetrachlorophenol which remained stable during the exposure of 14 weeks. Pentachlorophenol and tetrachlorophenol accumulated to some extent in the perirenal fat whereas only pentachlorophenol could be found in brain. A period of four weeks of chlorophenol-free diet was sufficiently long to allow removal of the major part of the chlorophenol burden. The neurochemical effects included increased acid proteinase activity at the 8th week of exposure. It levelled off while superoxide dismutase activity increased to twice the control level. Glial glutathione peroxidase activity did not change whereas glial glutathione concentration was below the control range at the 12th week of exposure. Cerebral diaphorase activity was below the control range initially, and its activity increased above the control level during the recovery period whereas other biochemical changes levelled off.

Adipose Tissue↗

Sensitive spectrophotometric method for determining pentachlorophenol in various environmental samples.

A new, simple, and sensitive spectrophotometric method is described for determination of pentachlorophenol, a widely used insecticide and herbicide, in various environmental samples. The method is based on the reaction of pentachlorophenol with concentrated nitric acid to form chloranil, which liberates iodine from potassium iodide. The liberated iodine then selectively oxidizes leucocrystal violet to form crystal violet, which has an absorption maximum at 592 nm. Beer's law is obeyed over the concentration range of 0.1-1.6 micrograms pentachlorophenol/25 mL (0.004-0.064 ppm). The method was applied satisfactorily to determination of pentachlorophenol in air, water, plant material, textile effluent, and biological samples.

Air Pollution↗

Biodegradation of pentachlorophenol (PCP) by white rot fungal strains screened from local sources and its estimation by high-performance liquid chromatography.

White rot fungal strains screened from local sources (wood trunks and from effluents of pulp and paper industry) were tested for their ability to biodegrade polymeric compounds, viz. polymeric dyes (crystal violet and brilliant green) and chlorinated phenol (pentachlorophenol). Two of the most promising strains showing maximum degradation of polymeric dyes were selected to study the biodegradation potential and pattern of biodegradation of pentachlorophenol (PCP), a commonly used leather preservative and a potential carcinogen. PCP was quantitatively estimated and analysed by high-performance liquid chromatography (HPLC). Conditions were optimized for the measurement of PCP on HPLC, which were: mobile phase, 60% acetonitrile and 40% water; flow rate, 1 mL/ min; column, mu Bondapack C18 RP and UV detector at 238 nm. One of the white rot fungal strains isolated from wood trunk showed a maximum 68% biodegradation of PCP in liquid-buffered medium in 16 days. The biodegradation pattern of PCP followed a pseudo-first-order kinetics. Studies on enhancement of biodegradation of polymeric dyes and PCP showed that the kinetics of biodegradation is greatly improved by the presence of manganese ions, H2O2 and glucose in the medium. This strongly suggests the involvement of peroxidase enzyme machinery of white rot fungus in the biodegradation process of PCP.

Biodegradation, Environmental↗

Chloracne associated with employment in the production of pentachlorophenol.

To evaluate the association between exposure to pentachlorophenol (PCP) and the occurrence of chloracne, we studied the medical and personnel records for individuals employed in the manufacturing of PCP. Forty-seven cases of chloracne were identified among 648 workers (7.0%) assigned to PCP production at a single plant between 1953 and 1978. The annual incidence rate varied considerably, ranging from 0 (in 1953) to 1.46 (in 1978). No linear trend in the risk of chloracne was observed with the duration of employment in the pentachlorophenol department. Workers with a documented episode of direct skin contact with PCP had a significantly increased risk of chloracne compared with workers who did not have a documented episode of direct skin contact (cumulative incidence ratio = 4.6; 95% confidence interval 2.6-8.1). Our results confirm that chloracne is associated with exposure to PCP contaminated with hexachlorinated, heptachlorinated, and octachlorinated dibenzo-p-dioxins and dibenzofurans.

Acne Vulgaris↗

Verification of the role of PCP 4-monooxygenase in chlorine elimination from pentachlorophenol by Flavobacterium sp. strain ATCC 39723.

The bacterial enzyme PCP 4-monooxygenase from Flavobacterium sp. strain ATCC 39723 catalyzes the oxygenolytic removal of the first chlorine from pentachlorophenol. PCP 4-monooxygenase is an FAD binding, NADPH requiring oxygenase, with similar functional domains as other bacterial flavoprotein monooxygenases specific for phenolic substrates. However, the definitive proof for the singular role of an oxygenolytic elimination of the primary chlorine from pentachlorophenol by Flavobacterium sp. has awaited the development of a genetic system whereby targeted mutagenesis via allelic exchange could be carried out with the corresponding gene from PCP 4-monooxygenase, pcpB. We report the development of a genetic system for Flavobacterium sp. strain ATCC 39723, and its application in targeted mutagenesis of the pcpB allele for elimination of PCP 4-monooxygenase activity.

Blotting, Southern↗