Effects Of Pentachlorophenol Research Articles

Effect of chronic In vivo exposure to pentachlorophenol on non-specific immune functions in Fundulus heteroclitus

The effects of pentachlorophenol (PCP) on non-specific immune function were studied in an estuarine fish, Fundulus heteroclitus. Following a 12-day in vivo exposure to a sublethal dose (50 ppb) of PCP, macrophages and eosinophils from the head kidney were isolated. These cells were then assayed for phagocytic activity, the production of superoxide onion (O 2 −) and luminol-enhanced chemiluminescence (LCL), a measure of the hydrogen peroxide (H 2O 2)-halide-peroxidase antibacterial system. The cells were also assayed for bactericidal activity against Listonella anguillarum, the agent responsible for vibriosis in fish. Macrophages and eosinophils isolated from fish exposed to this sublethal concentration of PCP showed no significant changes in the production of O 2 − or LCL following phagocytic stimulation with unopsonized yeast. The ability of macrophages to phagocytose FITC-conjugated yeast was not significantly affected by PCP exposure; however, these cells showed significantly decreased activity against Listonella. In contrast, eosinophils from PCP-treated fish were inhibited in their ability to phagocytose yeast, but their bactericidal activity was apparently not affected. In both phagocyte populations, basal levels of O 2 − and LCL produced by resting cells were significantly increased, a phenomenon which could contribute to oxidative stress in these fish. Previously, short-term in vitro exposures of Fundulus phagocytes to 10 ppm PCP showed reduced phagocytosis, O 2 − generation, LCL and bactericidal activity. At the end of the current in vivo studies, the pronephric PCP concentration was also ~ 10 ppm; this seemed to result in modulation of certain non-specific immune parameters, but significant bactericidal impairment was seen only in the macrophages.

Effect of pentachlorophenol on calcium accumulation in barnacle muscle cells.

1. The effect of extracellularly applied pentachlorophenol (PCP) was studied on the membrane potential (Vm) and Ca2+ uptake in isolated single skeletal muscle cells of Balanus nubilus. 2. When compared with the controls, 0.1 mM PCP induced a significant (P < 0.05) increase in Ca2+ uptake accompanied by membrane depolarization (9 mV at 45 min incubation). This depolarization was reduced by 11% of extracellular Ca2+ (Cao2+) was replaced by Tris+ and by 50% if extracellular Na+ was also replaced by Tris+. 3. The Ca2+ channel blocker, verapamil (0.1 mM), completely inhibited the PCP-induced Ca2+ uptake as well as the membrane depolarization either in the absence or presence of Cao2+. Experiments on voltage-clamped cells show that the PCP-induced Ca2+ uptake was independent of the PCP-induced depolarization. 4. The results indicate that PCP induces activation of a verapamil-sensitive Ca2+ influx pathway (presumably L-type Ca2+ channels) independent of Vm. The permeation of Ca2+, Na+ and Tris+ through this pathway produces membrane depolarization in the following order of effectiveness: Ca2+ > Na+ > Tris+.

Effects of pentachlorophenol (PCP) on the oxygen consumption rate of the river puffer fish Takifugu obscurus

Effects of pentachlorophenol (PCP) on the oxygen consumption rate of the river puffer fish Takifugu obscurus

Effects of Pentachlorophenol and Biotic Interactions on Soil Fauna and Decomposition in Humus Soil

In a laboratory experiment, effects of chemical stress (pentachlorophenol, PCP, at concentrations of 0, 50, and 500 mg/kg) and biotic interactions (nematodes in the presence or absence of collembolas and enchytraeids) on the community structure of soil animals and decomposition processes were studied. PCP was strongly adsorbed to humus that contained 65% organic matter. Numbers of fungal-feeding nematodes decreased significantly at the highest PCP concentration, while no effects were found in bacterial feeders. There were differences in the numbers of nematodes between different animal combinations, but at the highest PCP concentration, collembolas and enchytraeids had no effect on them. Numbers of collembola Willemia anophtalma were lowered at the highest PCP concentration, although PCP was not acutely toxic at this concentration. The highest PCP concentration was acutely toxic to enchytraeids, and for an unknown reason all of them died in the main experiment. Both ATP content of the soil and soil respiration were reduced at the highest PCP concentration, while no differences were found between animal treatments. Amounts of NH 4N and PO 4P in the soil increased with increasing PCP concentration. It was concluded that in the presence of simple animal communities, harmful chemicals like PCP regulate the community structure of soil animals as web as decomposition and nutrient mobilization.

Stimulatory and toxic effects of acid, pentachlorophenol or zinc on the mineralization of acetate in acid or calcareous soils and subsoils

Abstract The toxic effects of pollutants on the soil microflora was studied as part of a research program aimed at the setting of soil quality standards. The effects of pentachlorophenol, zinc or hydrochloric acid on the mineralization of 1 μg/L [14C] acetate to 14CO2 was studied in an acid surface soil, an acid subsoil, an calcareous surface soil and a calcareous subsoil. The chalky surface soil was most sensitive for pentachlorophenol (PCP) which caused a marked stimulation of the 14CO2 production at low doses. The chalky subsurface soil was most sensitive for zinc. The chalky soil and subsoil neutralized added HCl more rapidly and showed a stronger sorption of zinc compared with the acidic soils. Nevertheless these soils showed a much higher sensitivity for acid, zinc and also for pentachlorophenol. The microflora of the acid surface soil were relatively resistant to acid, PCP or zinc. This resistant microflora showed a relatively low acetate mineralization rate.

Effects of pentachlorophenol (PCP) on the pituitary and thyroidal hormone regulation in the rat

Investigations on rats after repeated application of pentachlorophenol (PCP) should clarify whether thyroid side effects caused by this xenobiotic can be seen in a dose range which does not cause major toxic effects. Female rats of the Wistar strain were treated with 3 and 30 mg PCP/kg body wt. daily by gavage for 28 days. To assess the potential impact of impurities the study was performed both with pure and technical grade PCP at the dosage of 3 mg · kg −1 · day −1, and at a level of 30 mg · kg −1· day −1 with pure PCP only. The effects in animals on normal iodine diet were compared to those in animals on a low iodine diet. No decrease of body wt. was noticed, only the liver weights were increased slightly in animals treated with 30 mg · kg −1· day −1 PCP. However distinct effects on thyroid hormones as well as on thyrotropin (TSH) were observed: a pronounced fall of circulating thyroxine (T 4) and triiodothyronine (T 3) levels was accompanied by lower levels of both free thyroid hormones and TSH, and the T 4:T 3 ratio was decreased in serum. Furthermore the intrathyroidal hormone stores were reduced. An interference of PCP at pituitary or hypothalamic level is assumed as a major mode of action. Additional effects of the test substance on peripheral conversion can be suspected.

Inhibition of phagocytosis and superoxide production by pentachlorophenol in two leukocyte subpopulations from Fundulus heteroclitus

The effect of pentachlorophenol (PCP) on non-specific immune function was studied in two phagocytic cell populations isolated from the pronephros of an estuarine fish, Fundulus heteroclitus. Macrophages and eosinophils were exposed to sublethal doses of PCP in vitro, then assayed for phagocytic activity and superoxide (O − 2) generation. Phagocytic activity was determined with a fluorescence concentration analyzer following incubation of the cells with FITC-conjugated yeast particles. Lucigenin-dependent chemiluminescence (CL) was used to measure superoxide production. Phagocytosis by both leukocyte populations was significantly inhibited at concentrations of PCP greater than 5 mg/liter; the production of O − 2 was significantly inhibited at PCP concentrations of 10 mg/liter or more. These two leukocyte populations play primary roles in cellular microbicidal and antiparasitic activities; therefore, the immunosuppression seen in these experiments suggests that exposure to sublethal levels of PCP could result in increased disease susceptibility.

Toxicity and estimated water quality criteria values in mallard ducklings exposed to pentachlorophenol

Tests were conducted to determine the effects of pentachlorophenol (PCP) in feed on growth and bioaccumulation in mallard ducklings (Anas platyrhynchos). Significant effects of PCP on growth (LOAEL) were observed after 11 days at 961 μg/g PCP. The NOAEL value (no significant growth effects) was 423 μg/g PCP. Concentrations of PCP in tissues at the NOAEL were 20.7 (liver), 12.2 (lipid), 3.3 (muscle), and 2.6 (brain) μg/g (wet wt); no bioaccumulation was observed. Using a toxicity threshold model, it was estimated that about 1.1 mg/L of waterborne PCP was a threshold for adverse effects for mallard ducks.

In vitro immunomodulation by pentachlorophenol in phagocytes from an estuarine teleost, Fundulus heteroclitus, as measured by chemiluminescence activity

Chemiluminescence (CL) was used to assay effects of pentachlorophenol (PCP) on the production of reactive oxygen intermediates (ROIs) generated by leukocytes from an estuarine teleost, Fundulus heteroclitus. Two parameters were measured during the phagocytically-induced respiratory burst: peak CL (maximal value) and total CL (temporal summation of induced values). Phagocytes obtained from the pronephros were incubated in the presence of sublethal doses of analytical (A-) or technical (T-) grades of PCP. Technical PCP has been reported to be more highly immunosuppressive than A-PCP in mammals; this effect was attributed to dioxins and other contaminants produced during manufacture. In this fish, both grades of the compound produced significant dose-dependent inhibition of peak and total CL. However, there were few significant differences between the effects of the two PCP grades on the magnitude of the CL responses at identical, sublethal concentrations, although T-PCP did produce a more marked reduction in the relative level of leukocytic CL as a function of dose than did A-PCP. Because of the probable roles of ROIs in antimicrobial blood cell-mediated mechanisms, reduced CL activity was interpreted as an indication of xenobiotic-induced immunosuppression.

Pentachlorophenol (PCP) inhibits ion transport in the isolated toad cornea

1. 1. Active chloride transport from the stroma to the epithelial surface (tear side) accounts for 80% of the amphibian cornea short-circuit current (SCC). 2. 2. The effect of pentachlorophenol (PCP, a wood preservative) on the bioelectric parameters of the toad Caudiverbera caudiverbera isolated cornea was studied. 3. 3. PCP applied to the epithelial surface in the concentration range 0.3–4.3 μM caused a dose-dependent inhibition of the PD and of the SCC in 7 corneas. This inhibition was irreversible at all concentrations after several washouts. The agent had no effect when applied to the endothelial surface. 4. 4. In 4 experiments the inhibitory effect was partly reversed by the addition of 1 μM calcium ionophore A-23187 to the epithelial surface. 5. 5. It is concluded that PCP is an inhibitor of corneal active chloride transport and that this structure shows greater sensitivity to this agent than other tissues.

Interactive effects of pentachlorophenol and temperature in the abalone ( Haliotis rufescens) as measured by in vivo 31P-NMR spectroscopy

The influence of temperature on the effects of pentachlorophenol (PCP) was described in red abalones ( Haliotis rufescens) using in vivo 31P nuclear magnetic resonance spectroscopy (NMR). Specifically, two effects were measured: the exposure times required for onset of PCP effects; and both intensity of, and recovery from, such effects. Following acclimation to clean seawater, abalones were exposed to a sublethal water concentration of PCP (1.2 mg l −1) at either 9 or 19°C until the spectral peak area for inorganic monophosphate (P i) was one-half that of phosphoarginine (PA); temperatures represented the seasonal range in California. The endpoint served to compare the times required to reach equivalent metabolic condition, and insured that all individuals were metabolically equivalent at the onset of exposure to clean seawater; abalones were maintained in clean seawater for up to 16 h to monitor recovery. In foot muscle, PCP caused a decrease in concentration of PA and ATP, an increase in that of P i, and acidification of intracellular pH; effects were produced more rapidly at 19°C, as the endpoint was attained in less than half the time (2.4 h) as was that at 9°C (5.4 h; P < 0.05). Both the average response to, and the average extent of recovery from, the biocide were greater in abalones exposed at 19°C. Upon exposure to clean seawater, all effects generally reversed within 10 to 16 h, and control abalones maintained at the two temperatures alone exhibited no adverse effects. Finally, abalones exposed to 120 μg l −1 of PCP for 18 h at both 9 and 19°C exhibited no adverse effects, indicating that PCP does not impact abalones at current environmental concentrations. In conclusion, high temperature potentiates the time both to onset of and for recovery from the sublethal effects of PCP in the red abalone. Use of in vivo NMR allows measurement of multiple-stress interactions in live, intact aquatic organisms, facilitating the detailed elucidation of individual responses and the laboratory assessment of the environmental effects of pollutants.

Toxicological and immune findings in workers exposed to pentachlorophenol (PCP).

Pentachlorophenol (PCP) is a pesticide used worldwide in industrial and domestic applications. Data available on the effects of technical-grade PCP on the immune system are insufficient and equivocal; some data indicate inhibitory effects, whereas others suggest stimulating effects. This study was performed to evaluate toxicological and immune findings in 32 subjects who had prolonged exposure to PCP in a wood factory and in 37 controls. PCP concentrations were determined in plasma and urine of all subjects. Lymphocyte subsets of CD3-, CD4-, and CD8-positive cells were evaluated, and the proliferative response of peripheral blood mononuclear cells (PBM) to mitogens was assessed. The results suggested the absence of major laboratory and clinical signs of PCP-dependent immune deficiency. A weak effect of long-term exposure to PCP on the functional immune response could not be ruled out because of the finding of a decreased response to 5% PHA in the high-exposure group. A weak effect against hepatocyte membrane was evidenced by the finding of raised serum concentration of glycocholic, taurodeoxycholic, and glycochenodeoxycholic acids in subjects directly exposed to PCP for more than 10 y.

Characterization of a novel Pseudomonas sp. that mineralizes high concentrations of pentachlorophenol.

A pentachlorophenol (PCP)-mineralizing bacterium was isolated from polluted soil and identified as Pseudomonas sp. strain RA2. In batch cultures, Pseudomonas sp. strain RA2 used PCP as its sole source of carbon and energy and was capable of completely degrading this compound as indicated by radiotracer studies, stoichiometric release of chloride, and biomass formation. Pseudomonas sp. strain RA2 was able to mineralize a higher concentration of PCP (160 mg liter-1) than any previously reported PCP-degrading pseudomonad. At a PCP concentration of 200 mg liter-1, cell growth was completely inhibited and PCP was not degraded, although an active population of Pseudomonas sp. RA2 was still present in these cultures after 2 weeks. The inhibitory effect of PCP was partially attributable to its effect on the growth rate of Pseudomonas sp. strain RA2. The highest specific growth rate (mu = 0.09 h-1) was reached at a PCP concentration of 40 mg liter-1 but decreased at higher or lower PCP concentrations, with the lowest mu (0.05 h-1) occurring at 150 mg liter-1. Despite this reduction in growth rate, total biomass production was proportional to PCP concentration at all PCP concentrations degraded by Pseudomonas sp. RA2. In contrast, final cell density was reduced to below expected values at PCP concentrations greater than 100 mg liter-1. These results indicate that, in addition to its effect as an uncoupler of oxidative phosphorylation, PCP may also inhibit cell division in Pseudomonas sp. strain RA2.(ABSTRACT TRUNCATED AT 250 WORDS)

Inhibition of the sodium transport by pentachlorophenol (PCP) in toad skin ( Pleurodema thaul)

1. The effects of pentachlorophenol (PCP) were studied in vitro on an active ionic transporting epithelium. Ussing's technique was applied on the isolated Pleurodema thaul skin. 2. Concentrations of PCP in the range 0.003–0.043 mM caused an irreversible dose-dependent inhibition in both the short-circuit current and the potential difference. 3. Parameters of an electrical equivalent circuit were calculated applying the Isaacon's amiloride test. 4. It was also shown that PCP produced a significant increase in the O 2 consumption of the skin. 5. The inhibitory action of PCP on active sodium transport in terms of the equivalent electrical circuit and the increased oxygen consumption points to an uncoupling action of PCP on the oxidative phosphorylation.

Interactive effects of pentachlorophenol and hypoxia in the abalone ( Haliotis rufescens) as measured by in vivo 31P NMR spectroscopy

The effects of hypoxia and pentachlorophenol (PCP) were investigated in red abalones ( Haliotis rufescens) using flow-through exposure and in vivo 31P nuclear magnetic resonance spectroscopy (NMR). Following acclimation to clean seawater, three abalones were separately exposed to a 6-h sublethal concentration of PCP (1.2 mg 1 −1) until the spectral resonance for inorganic monophosphate (P i) was half-height to that of phosphoarginine (PA); the endpoint assured that all individuals were metabolically equivalent at the start of air exposure. They were exposed to clean seawater for 2 h to allow the effects from PCP to stabilize, then air for 45 min, and finally clean seawater for 15 h to check recovery. The effects of PCP in foot muscle included a decrease in the concentrations of PA and adenosine triphosphate ([PA] and [ATP], respectively), an increase in P i, and a decrease in intracellular pH (pH i). Upon air exposure, [PA] and pH i rapidly declined further, [P i] increased, and [ATP] did not change; the magnitudes were similar to those from emergence alone. After resubmergence, both [PA] and [P i] recovered rapidly from the effects of hypoxia, but slowly from those of PCP. While pH i initially declined further, both [ATP] and pH i recovered to near-initial levels after 15 h. In general, the metabolic effects of hypoxia did not change upon pretreatment with PCP; the biochemical interaction of the two factors was additive. Another three abalones were separately exposed to PCP at an environmentally relevant concentration of 120 μg 1 −1 for 6 h, air for 1 h, then the same PCP concentration for 2.5 h to check recovery. At the lower concentration, PCP produced no discernable effects, and those of hypoxia were similar to those without PCP. Since PCP produced no additional effects with or without hypoxia, it does not significantly impact red abalones at currently measured environmental concentrations. Use of in vivo NMR allows measurement of the interactive effects of multiple stress factors in live aquatic organisms, allowing assessment of the actual environmental effects of pollutants in the laboratory.

Sublethal effects of pentachlorophenol in the abalone (haliotis rufescens) as measured by in vivo 31P NMRSpectroscopy

The sublethal biochemical effects of pentachlorophenol (PCP) were investigated in live, intact red abalones (Haliotis rufescens), using a flow-through exposure system, by in vivo 31P NMR spectroscopy. Based on rangefinding tests (6-hr LC50 = 1.6 mg/L; 6-hr no-observable-effect-level (NOEL) = 0.8 mg/L), three abalones were separately exposed to a sublethal concentration (1.2 mg/L) for 5 hr, followed by a 13 hr recovery period. Effects in foot muscle included both a decrease in phosphoarginine and an increase in inorganic monophosphate concentrations ([PA] and [Pi], respectively); both foot muscle concentrations of adenosine triphosphate [ATP] and intracellular pH (pHi) also declined. Parallel in vitro experiments revealed that concentrations of glycerol 3-phosphate, lactate, citrate, succinate, malate, and alanine (Ala) all increased, while those of glyceraldehyde 3-phosphate and glutamine (Gln) remained stable. Also, these effects were not evident until 2 hr into exposure, possibly the time required for PCP to attain an effective concentration in foot muscle. During recovery, while Pi declined to pre-exposure levels, [PA] completely recovered in only one individual. Also, realkalinization of pHi was similar to recovery of [Pi], and ATP returned to near-initial levels, as did glycerol 3-phosphate, lactate, succinate, malate, and Ala; glyceraldehyde 3-phosphate, citrate, and Gln levels declined. Recovery responses corresponded to the time for PCP clearance from foot muscle. The effects of PCP were similar to those of hypoxia, fatigue, hypersalinity, and arginine kinase inhibitors, and so sublethal PCP concentrations may also inhibit electron transport and arginine kinase as well as uncouple mitochondrial oxidative phosphorylation in intact molluscs. Thus, the effects of pollutants on key biochemical processes may now be measured in intact aquatic organisms as they occur, improving our ability to accurately assess the environmental effects of pollutants in the laboratory.

Potentiation of 2,6-dinitrotoluene genotoxicity in Fischer 344 rats by pretreatment with pentachlorophenol

The organochlorine pesticide, pentachlorophenol, a potent sulfotransferase inhibitor, reportedly reduces the binding of 2,6-dinitrotoluene, an industrial hepatocarcinogen to hepatic DNA by 95% after a single i.p. injection. Activation of 2,6-dinitrotoluene to genotoxic metabolites involves enzymes in both the liver and the intestinal flora. Since pentachlorophenol also has bactericidal activity and induces hepatic mixed function oxidase activity after longer treatment, the effect of pentachlorophenol on intestinal enzyme activity and the biotransformation of 2,6-dinitrotoluene to genotoxic metabolites was studied after 1, 2, 4, and 5 weeks of treatment. Male Fischer 344 rats were dosed daily, by gavage, with either 20 mg/kg pentachlorophenol or the peanut oil vehicle. After 1, 2, 4, and 5 weeks, select control and treated animals were injected p.o. with 75 mg/kg 2,6-dinitrotoluene and transferred to metabolism cages, where urine was collected for 24 hr and tested for mutagenic activity by the Ames Salmonella typhimurium reversion assay. At 2 and 4 weeks, six control and six treated animals were sacrificed and nitroreductase, azo reductase, β-glucuronidase, dechlorinase, and dehydrochlorinase activities were analyzed in homogenates of the small intestine, large intestine, and cecum. At 5 weeks, hepatic DNA adduct formation was assayed by the 32P-postlabeling of DNA. Results from this study indicated that pentachlorophenol accelerated the biotransformation of 2,6-dinitrotoluene to genotoxic metabolites and potentiated the formation of 2,6-dinitrotoluene-induced DNA adducts in the liver. This is the first report of a chemical interaction leading to increased DNA adduct formation and indicates that chemical interactions could be important to risk assessment since they alter the relationship between exposure, dose, and the effect of genotoxicants.

Effect of pentachlorophenol on the activation of 2,6‐dinitrotoluene to genotoxic urinary metabolites in CD‐1 mice: A comparison of GI enzyme activities and urine mutagenicity

2,6-Dinitrotoluene (2,6-DNT) and pentachlorophenol (PCP) are used for industrial purposes and are found in the environment as hazardous contaminants. Because concurrent exposure to both compounds can occur, it is of interest to determine if organochlorine compounds potentiate the effect of nitroaromatic chemicals. CD-1 mice were treated with PCP (42.8 mg/kg) for 4 weeks. On weeks 1, 2, and 4 after the initial PCP dose, mice were treated p.o. with 2,6-DNT (75 mg/kg) and 24 hr urines were collected. After concentration, the urines were tested for their mutagenic activity in Salmonella typhimurium strain TA98 without metabolic activation in a microsuspension bioassay. A significant increase (P less than .05) in mutagenicity was observed in urines from mice treated with 2,6-DNT alone and in combination with PCP. By week 4, mice that received both 2,6-DNT and PCP excreted urine that was more mutagenic than that from animals which received only 2,6-DNT. At weeks 2 and 4, mice were sacrificed and intestinal enzyme activities (nitroreductase, azo reductase, beta-glucuronidase, dechlorinase, and dehydrochlorinase) were quantitated. The enhanced genotoxicity observed in urines from 2,6-DNT/PCP-treated mice coincided with a decrease in nitroreductase and an increase in beta-glucuronidase activities in the small intestine.

Effects of pentachlorophenol and 2,4,5-trichlorophenoxyacetic acid on the microflora of the soil in a beech wood

Every second month for 2 years a beech forest floor was treated with pentachlorophenol and 2,4,5-trichorophenoxyacetic acid each in two concentrations. The microbial biomass and its respiration activity in the three litter horizons were measured during this time and during a recovery period of 2 years after the treatment was stopped. The microbial biomass, mainly fungi, was decreased dose-responsively, as was the respiration rate. The doubling time of the fungal biomass was estimated to be about 50–100 days in the F horizon, and considering the natural decreases and recovery times observed, it is suggested, following Domsch et al. (1983), that a biomass decrease of 75%–93.75% is tolerable, a decrease of less than 75% is negligible, and a decrease of over 93.75% is critical.

The effect of pentachlorophenol and its metabolite tetrachlorohydroquinone on cell growth and induction of DNA damage in Chinese hamster ovary cells

It is shown that p-tetrachlorohydroquinone (TCH), the metabolite of the environmental chemical pentachlorophenol (PCP), is more toxic to cultured CHO cells than PCP, and that it causes DNA single-strand breaks and/or alkali-labile sites at concentrations of 2–10 μg/ml as demonstrated by the alkaline elution technique.