Effects Of Methyl Parathion Research Articles

The Effect of Methyl Parathion on The Pyruvate Kinase Enzyme Activity

Metil paration, tarımda ve genel alanlarda zararlılara karşı kullanılan organofosfat grubu bir insektisittir. İnsektisitlerin çevre ve canlı organizmalar üzerinde önemli derecede toksik etkileri bulunmaktadır. İnsanlarda farklı toksisiteye neden olan Metil paration’un metabolizmayı kontrol eden önemli enzimleri etkilediği bilinmektedir. Allosterik özellik gösteren Piruvat kinaz (EC.2.7.1.40), glikolizin son enzimidir ve glikoliz ile devamındaki moleküler yolaklarda kontrolü sağlamaktadır. Çalışmamızda Metil paration’nun Piruvat kinaz enzim aktivitesi üzerine etkisi araştırıldı. Metil paration’un LD50 dozu (7mg.kg-1) intraperitoneal olarak farklı periyotlarla (2, 4, 8, 16, 32, 64 ve 72 saat) erkek ve dişi sıçanlara uygulandı. Sıçanların karaciğer, böbrek, beyin ve ince bağırsak dokularında Piruvat kinaz enzim aktivitesi analiz edildi. Metil paration maruziyeti sonucunda sıçan dokularında genel olarak Piruvat kinaz enzim aktivitesinde artışlar belirlendi. Bu aktivasyonların özellikle beyin dokusunda daha erken saatlerde gerçekleşmiş olması dikkat çekicidir. Karaciğer, böbrek ve ince bağırsak dokularında aktivasyonların dişilerde erkeklerden daha erken saatlerde olduğu gözlendi. Sonuç olarak bir insektisit olan Metil paration uygulamasının sıçan dokularında piruvat kinaz enzim aktivitesinde artışlara neden olduğu bulundu. Metil parationun glikoz metabolizmasını ve buna bağlı olarak diğer metabolik yolakları etkilediği tartışıldı. Bu nedenle Metil paration insektisitinin metabolizmayı etkilediği, farklı sağlık sorunlarına neden olabileceği düşünülmeli ve Dünya Sağlık örgütünün önerdiği uygulama dozuna dikkat edilerek güvenli kullanım için önlemler alınmalıdır.

Effect of Commercial Grade Methyl Parathion on the Survival of Pseudomonas at Varying Temperature and pH

The wide-spread use of methyl parathion as an agricultural insecticide has been causing an increased level of contamination in soil, vegetation and groundwater reservoirs and as well as adverse effects on human, flora, fauna and ecosystems. Therefore, eco-friendly and cost-effective bioremediation system are needed to remove these pollutants from the contaminated sites and mitigate its hazardous. For this purpose, a lab scale study was conducted to investigate the effect of high concentrations of commercial grade methyl parathion (50 EC) on growth of indigenous soil Pseudomonas IES-Ps-1 under different environmental conditions such as pH and temperature. To determine the tolerance limit, Pseudomonas IES-Ps-1 was grown in nutrient broth supplemented with methyl parathion (0, 200, 400, 600, 800, 1000 and 1200 mg/l). The detailed pH (6, 7, 9) and temperature (25, 30 and 35 oC) studies were conducted using higher methyl parathion (400 and 800 mg/l). No growth was observed at 1000 and 1200 mg/l of pesticide after 96 hrs of incubation compared to other concentrations of 200, 400, 600 and 800 mg/l. The maximum growth for both 400 and 800 mg/l of pesticide was observed at pH 7 and 30 °C. The maximum removal of total organic carbon and chemical oxygen demand for 400 mg/lof pesticide were found 50 and 52 % while those for 800 mg/l were 46 and 49 % respectively. Hence, this study concluded that indigenous soil bacterium Pseudomonas IES-Ps-1 could serve as an efficient candidate at 30 °C and pH 7 in development of a bioremediation system for the removal of toxic effects of methyl parathion like pesticides from contaminated sites.

Effects of methyl parathion on Oscimum americanum L. infected with fungus Fusarium oxysporum

The pathogen Fusarium oxysporum during its different stages of growth-mycelia, mat of mycelia, microconidia and megaconidia-liberates several toxic substances that either inactivate the cells or lysis of even xylem and phloem tissues of the host plant Oscimum americanum.

Effect of methyl parathion and chlorpyrifos on certain biomarkers in various tissues of guppy fish, Poecilia reticulata

Tests of acute toxicity were performed on the most common species of aquarium fish, Poecilia reticulata. Guppies ( P. reticulata) were exposed to progressive concentrations of methyl parathion (MP) and chlorpyrifos (CPF); a semi-static method according to guidelines of OECD was used. Tests of acute toxicity were conducted using 10 fish for each separate concentration and for the control group. The results were subjected to probit analysis to determine the 96 h LC 50 values. The 96 h LC 50 values of MP and CPF to P. reticulata were 8.48 ppm/L (5.98–10.89) and 0.176 ppm/L (0.313–0.224) respectively. In addition, behavioral changes at each concentration were observed for the individual fish. Fish were exposed for 96 h to different sublethal concentrations of MP and CPF (¼ LC 50, 1/8 LC 50 and 1/10 LC 50) and their oxidative stress-induction potential was estimated in brain, liver and gills of fish. MDA content is induced in all tissues but maximum rise was observed in gills (161% and 153% for MP and CPF respectively). With regard to antioxidant defense system (ADS), GSH level decreased in the brain, liver and gills of tissues of MP treated fishes (22%, 6% and 13% respectively) and showed increase in brain and gills CPF treated (23% and 21% respectively). CAT, GST, GR and SOD levels fluctuated in all treatment groups relative to the control. Brain AChE showed dose-dependent inhibition in fish exposed to the higher concentrations reached 45% and 66% for MP and CPF respectively. Collective findings demonstrated that pesticide exposure of fish induced an increase in MDA and fluctuated ADS along with inhibited AChE. These findings may be used as valuable biomarkers for evaluation of water pollution.

Effect of methyl parathion on nitrous oxide production: A laboratory study

We investigated the diversity of a denitrifying gene (nirK) and the emission of CO(2) and N(2)O, in a "chinampa" soil contaminated with methyl parathion. Soil at 40% of water holding capacity was spiked with methyl parathion at four concentrations (i.e. 0, 0.7, 1.47 and 4.27 g kg(-1) dry soil), while emission of N(2)O and CO(2) and nirK diversity was determined after 0, 1, 14, 30, 60 and 90 days. The emission of N(2)O on a daily base and the cumulative emission of CO(2) was not affected by the different concentrations of methyl parathion applied to soil. The diversity of the nirK gene, determined by using temperature gradient gel electrophoresis (TGGE), decreased with increased methyl parathion application. It was found that methyl parathion had effect on the emissions of N(2)O and CO(2), and reduced the diversity of the nirK gene. Consequently, the reduced diversity of the nirK gene could affect the emission of N(2)O.

Effect of methyl parathion on the muscle and brain acetylcholinesterase activity of matrinxã (Brycon cephalus)

Farming of the freshwater fish is emerging in Brazil and many species from the wild are promising. The teleost matrinxã (Brycon cephalus) holds several characteristics such as fast growth rate, high commercial value and adaptability to artificial raring conditions, which make it a promising species for commerce. The use of pesticides in aquatic environment is frequent in Brazil, and methyl parathion is very common in aquaculture. We have determined the enzymatic activity of acetyl cholinesterase in white muscle and brain of matrinxã exposed to 2ppm of environmental methyl parathion for 24 hours. There was 64% and 69% of acetyl cholinesterase inhibition in muscle and brain respectively. These activities were not recovered after 8 days from exposure to this pesticide. It can be concluded that acetyl cholinesterase from those tissues was inhibited by small amounts of methyl parathion, and the main effect was observed in the brain.

Effects of methyl parathion ( o, o-dimethyl o-4-nitrophenyl phosphorothioate) on rat sperm morphology and sperm count, but not fertility, are associated with decreased ascorbic acid level in the testis

Methyl parathion (MP; o, o-dimethyl o-4-nitrophenyl phosphorothioate) is an organophosphorous pesticide used world wide to spray agricultural crops. The present study was aimed to investigate the genotoxic and cytotoxic effects on male germ cells and their possible relation with testicular ascorbic acid levels. Adult male Wistar rats ( n = 5/group) received MP at 0, 0.5, or 1 mg/kg (experiments 1 and 2) for 12 days and 0, 0.75 or 1.5 mg/kg (experiment 3) for 25 days (i.p.) everyday at intervals of 24 h. The epididymal sperm count, sperm abnormalities and testicular ascorbic acid levels (by 2,4-dinitrophenyl hydrazine method) were estimated on days 130, 77 and 17 following the last exposure in experiments 1, 2, and 3, respectively. Virgin untreated female rats were mated with treated males from experiments 2 and 3 for a week effective from day 35 to 41 after the first treatment, and fertility indices were measured after the birth of pups. Sperm count was decreased in experiments 2 and 3 ( P < 0.01), and in all three experiments, the abnormal sperms increased ( P < 0.001). Concomitantly, the ascorbic acid levels decreased in the testis ( P < 0.05–0.001; one-way ANOVA and Bonferroni's post hoc test). The body weights of offspring of treated males did not show significant changes from those of the controls, although there were some decreases observed. MP reduced the lactation index in experiment 2 ( P < 0.001; Chi-square test). The number of pups/parent along with fertility indices showed some numerical decrease but without any statistical significance. The present findings suggest that MP is a weak genotoxic and cytotoxic agent in the rat exposed to human exposure dose-levels, and that these effects, except the fertility are well correlated with decreased ascorbic acid level in the testis. Furthermore, MP-induced changes in the germ cells do not have any significant effects on F 1 generation.

Methyl parathion increases neuronal activities in the rat locus coeruleus

Exposure to organophosphate insecticides induces undesirable behavioral changes in humans, including anxiety and irritability, depression, cognitive disturbances and sleep disorders. Little information currently exists concerning the neural mechanisms underlying such behavioral changes. The brain stem locus coeruleus (LC) could be a mediator of organophosphate insecticide-induced behavioral toxicities since it contains high levels of acetylcholinesterase and is involved in the regulation of the sleep-wake cycle, attention, arousal, memory, and pathological processes, including anxiety and depression. In the present study, using a multi-wire recording technique, we examined the effects of methyl parathion, a commonly used organophosphate insecticide, on the firing patterns of LC neurons in rats. Systemic administration of a single dose of methyl parathion (1 mg/kg, i.v.) increased the spontaneous firing rates of LC neurons by 240% but did not change the temporal relationships among the activities of multiple LC neurons. This dose of methyl parathion induced a 50% decrease in blood acetylcholinesterase activity and a 48% decrease in LC acetylcholinesterase activity. The methyl parathion-induced excitation of LC neurons was reversed by administration of atropine sulfate, a muscarinic receptor antagonist, indicating an involvement of muscarinic receptors. The methyl parathion-induced increase in LC neuronal activity returned to normal within 30 min while the blood acetylcholinesterase activity remained inhibited for over 1 h. These data indicate that methyl parathion treatment can elicit excitation of LC neurons. Such excitation could contribute to the neuronal basis of organophosphate insecticide-induced behavioral changes in human.

Effect of methyl parathion on the susceptibility of shrimp Litopenaeus vannamei to experimental vibriosis

Following increasing calls for environmental safety over the past 2 decades, persistent pesticides are being replaced by more rapidly degradable products. However, even these pesticides can affect non-target species, and may be associated with slow growth and increased susceptibility to viral and bacterial infections. In this study, juvenile white shrimp Litopenaeus vannamei (also named Penaeus vannamei) were challenged by intramuscular injection with Vibrio parahaemolyticus after 4 d prior exposure to methyl parathion in feed pellets at 0.080 microg g(-1). The bacterial injection control group consisted of shrimp fed pellets containing the methyl parathion-carrier solvent acetonitrile. Three additional control groups comprised 2 sterile saline-injection groups fed pellets containing methyl parathion or acetonitrile prior to injection, and 1 uninjected group fed normal pellets. Cumulative mortalities were recorded on the 4th and 8th days, and the presence of histological lesions was recorded on the 8th day. Cumulative mortalities were significantly higher in the group exposed to methyl parathion and bacteria on Day 8. Histological lesions, typical of vibriosis, were significantly associated with the injection of V. parahaemolyticus. The study provides strong experimental evidence that prior exposure to methyl parathion can increase the severity of Vibrio infections.

Effects of Methyl Parathion on White-Winged Dove Productivity and Reproductive Behavior

Recent analyses suggest that exposure to cholinesterase (ChE)-inhibiting pesticides may be a factor contributing to declines of white-winged dove (Zenaida asiatica) populations in the Lower Rio Grande Valley (LRGV) of Texas, USA. Because irrigated cotton fields are regularly sprayed with organophosphorus (OP) pesticides (known ChE inhibitors) and doves drink irrigation water, we conducted a series of experiments to determine effects of OP pesticides in drinking water on productivity and reproductive behavior of white-winged doves. During the breeding seasons of 1996-1998, we exposed captive breeding pairs of white-winged doves to various concentrations of methyl parathion (MP), an OP pesticide widely used in the LRGV. Exposure to drinking water with 1.0 ppm MP did not significantly affect reproduction. Exposure to ≥4.5 ppm MP primarily affected egg laying and incubation stages of the reproductive cycle. Specifically, both chronic and periodic exposure to MP-contaminated water reduced number of eggs laid/pair, time incubating, and number of chicks fledged/pair. Food and water consumption declined with exposure to MP. Responses of white-winged doves to MP exposure were consistent with the hypothesis that declines in dove populations in the LRGV are influenced by pesticide exposure. However, field evidence of direct exposure is required to support the hypothesis of a pesticide-related decline.

In vitro cytotoxicity of the organophosphorus insecticide methylparathion to FG-9307, the gill cell line of flounder (Paralichthys olivaceus).

FG-9307, a cell line derived from the gill of flounder Paralichthys olivaceus, was used to determine the acute cytotoxic effects of the organophosphorus insecticide methylparathion. The cytotoxic effects of methylparathion were initially measured by three endpoint systems: neutral red (NR) uptake assay, tetrazolium (MTT) assay, and cell protein assay. Results indicated that concentrations of methylparathion ranging from 5 microg/ml to 60 microg/ml were toxic, and there was no significant difference in cytotoxic effects between the three test systems. Thus, the FG-9307 cell line is one of several choices for evaluating the acute toxicities of organophosphorus insecticides such as methylparathion. The ultrastructure of the cells was also studied. It was found that the ultrastructure of the cells was markedly altered by methylparathion, as evidenced by dilation of mitochondria, breakdown of rough endoplasmic reticulum, nuclear necrosis, and production of numerous lysosomes and lipid vacuoles. This appears to be the first report that a marine fish cell line can be used for acute in vitro cytotoxicity evaluation of methylparathion.

Effects of methyl parathion on reproduction in the Japanese quail.

Effects of methyl parathion on reproduction in the Japanese quail.

Effects of Methyl Parathion and Tri-miltox on the Mitosis of Allium cepa.

Treatment of Alium cepa seeds with different concentrations of Methyl parathion (insecticide) and Tri-miltox (fugicide) induced different types of chromosomal aberrations, such as micronuclei, chromosomal fragments, laggard chromosomes, single and multiple bridge formation. Maximum number of cells were observed with micronuclei, then with bridges and the minimum with laggard chromosomes. Methyl parathion produced comparatively more chromosomosomal aberrations than Tri-miltox. Comparing the three treatments applied, seed treatment produced maximum chromosomal aberrations, and the root treatment with recovery period produced the minimum chromosomal aberrations with the root treatment occupying the intermediate position.

Growth, chlorophyll a content, nitrogen-fixing ability, and certain metabolic activities ofNostoc muscorum: Effect of methylparathion and benthiocarb

Growth, chlorophyll a content, nitrogen-fixing ability, and certain metabolic activities ofNostoc muscorum: Effect of methylparathion and benthiocarb

Effects of methyl parathion on northern bobwhite survivability

AbstractThe effects of methyl parathion on survivability of wild northern bobwhites (Colinus virginianus) were investigated from 1986 to 1988 near Tallahassee, Florida. In three field seasons, 197 bobwhites were administered 0, 2, 4 or 6 mg/kg methyl parathion in corn oil by oral intubation, released and monitored for 14 d using radio telemetry. Bobwhites receiving 6 mg/kg methyl parathion had lower survival (P = 0.022) than control birds due to predation, not overt toxicity. There were no differences (P &gt; 0.05) among treatment groups in activity, but methyl parathion may have influenced covey integrity. Birds that survived methyl parathion treatment had brain cholinesterase activities similar to those of control bobwhites. The results suggest that if bobwhites receive sufficiently high methyl parathion exposure in their natural habitats, then their susceptibility to predation may increase.

Inhibition of acetylcholinesterase and butyrylcholinesterase by the organophosphorus insecticide methylparathion in the central nervous system of the golden hamster (Mesocricetus auratus)

The toxic effects of the organophosphorus pesticide methylparathion are primarily caused by the inhibition of acetylcholinesterase activity in the central nervous system, whereas the relationship between butyrylcholinesterase and poisoning symptoms is unclear. The presumed different effects of methylparathion on acetylcholinesterase in various regions of brain and spinal cord suggest differences in the distribution of molecular enzyme forms. In the present work, the in vitro and in vivo effects of methylparathion on acetylcholinesterase and butyrylcholinesterase were studied in whole brain homogenates of golden hamsters with biochemical methods. Furthermore, acetylcholinesterase activity was determined in regions of the nervous system by quantitative histochemistry (microdensitometry). Biochemically, very low IC50 values of the hydrophilic and lipophilic fractions of both enzymes were measured. Analysis of the time course of enzyme inhibition revealed maximum inhibition 45 min after methylparathion application. Using microdensitometry different degrees of acetylcholinesterase inhibition were found in various areas of the brain. The highest inactivation was observed in the Substantia nigra and in thalamic nuclei; in several regions of the cerebellum, the inhibition rate was comparatively lower. In conclusion, methylparathion acts as an potent inhibitor of acetylcholinesterase and butyrylcholinesterase in the hamster nervous system. The region-specific different inactivation of acetylcholinesterase might be caused by the existence of multiple forms of the enzyme in various brain regions.

Effects of methyl parathion on red-winged blackbird (Agelaius Phoeniceus) incubation behavior and nesting success

Free-living female red-winged blackbirds (Agelaius phoeniceus) were captured on their nests and given oral doses of 0, 2.37 or 4.21 mg/kg methyl parathion in a propylene glycol carrier during incubation. Birds were released immediately after dosing and observed for 5 h to document behavioral effects, amount of time spent off the nest after dosing and time spent incubating. Each nest was monitored until nestlings fledged or until all nestlings died or disappeared. For each nest, the time of abandonment, hatching success and fledging success were determined. In addition, prefledging weights were obtained for all nestlings in nests at 8 d after hatch. Although methyl parathion caused ataxia, lacrimation and lethargy and significantly depressed cholinesterase activity (>35%) at 4.21 mg/kg, there were no apparent adverse effects on reproduction. Females receiving 4.21 mg/kg methyl parathion were able to return to their nests, resume incubation, successfully hatch their clutch and rear their young. Nestlings of poisoned females did not have significantly different body weights at 8 d compared to controls, indicating that methyl parathion did not disrupt the females' ability to forage and deliver adequate food to nestlings. Band returns from the following year indicated that treatment birds returned and nested in nearly the same proportion as did controls and other red-winged blackbirds occupying the ponds. There was no indication that a single oral dose of methyl parathion (2.37 or 4.21 mg/kg) decreased over-winter survival.

Effect of methyl parathion on food discrimination in northern bobwhite (Colinus virginianus)

AbstractThe effect of methyl parathion on dietary discrimination ability was assessed in two‐week‐old northern bobwhite (Colinus virginianus). An initial oral dose of methyl parathion (0, 3 or 6 mg/kg: O,O‐dimethyl O‐(4‐nitrophenyl) ester) was given to two subgroups of bobwhite before a 6‐d food discrimination test; one group was tested with a choice of food treated with 45 ppm methyl parathion versus normal food and the second with a choice of 90 ppm treated food versus normal food. The average discrimination ratios (i.e., amount of treated to untreated food consumed) were used to indicate the chicks' ability to discriminate and avoid contaminated food. Chicks administered 6 mg/kg methyl parathion did not discriminate between treated and untreated food at either food treatment level and initially chose treated over untreated food (ratio = 1.28; p &lt; 0.05). Brain cholinesterase activity in the 6 mg/kg groups averaged 50% of control levels, indicating high exposure to methyl parathion, which correlated with a behavioral disturbance (i.e., preference for treated food on day 1). Cholinesterase activity did not correlate with the discrimination ratios throughout the remainder of the 6‐d exposure period due to the strong side preference that developed in the treated groups. This study demonstrates that feeding behavior and taste discrimination ability of bobwhite chicks was impaired due to exposure to methyl parathion.

Chronic dose effects of methyl parathion on nuthatches: cholinesterase and ptilochronology.

The widespread use of organophosphorus (OP) insecticides in agriculture has caused increased concern for the potential exposure to wildlife. Some effects of OPs on wildlife include loss of body weight (Grue 1982), reproductive effects (Stromborg 1977, 1981; Spyker and Avery 1977), susceptibility to environmental stress (Pope and Ward 1972), reductions in visual acuity, vigilance, and food-seeking behavior (Grue et al. 1983), hypothermia (Chattopadhyay et al~ 1982) and death.

Effects of methyl parathion in ducks and duck broods

AbstractNesting ducks (mallards, blue‐winged teal, cinnamon teal and wood ducks) were trapped, equipped with radio transmitters and released on two agricultural fields, both of which were bordered by waterways. One field was aerially treated with methyl parathion at the rate of 1.4 kg active ingredient (a.i.)/ha and the second field was an untreated control. Ducks were located with the aid of radiotelemetry after pesticide application and their activity monitored daily in both fields. Brood abandonment by hens and nesting hen mortality occurred only on the methyl‐parathion‐treated field postspray. Brain cholinesterase levels were significantly depressed in two of three nesting hens. Fifty‐eight percent of the 37 ducklings present in the control field on the day of spray survived to day 22 postspray. Sixteen percent of the 24 ducklings present in the treated field on the day of spray survived to day 22. The average daily rate of duckling loss was also greater in the treated field than in the control field. Nest abandonment rates could not be correlated with methyl parathion application.