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Residue Reviews 1971
Review
Topics: Acute Disease; Animals; Birds; Carbamates; Cattle; Chronic Disease; Dogs; Drug Compounding; Female; Fishes; Lethal Dose 50; Male; Mice; Organophosphorus Compounds; Rats; Time Factors
PubMed: 4937707
DOI: 10.1007/978-1-4615-8473-5_5 -
Residue Reviews 1971
Review
Topics: Biological Assay; Carbamates; Cholinesterase Inhibitors; Chromatography, Gas; Chromatography, Paper; Ethylamines; Methods; Organophosphorus Compounds; Plants, Edible; Spectrum Analysis
PubMed: 4937706
DOI: 10.1007/978-1-4615-8473-5_7 -
The setting of an occupational exposure limit for phosphamidon in the workplace--a Chinese approach.The Annals of Occupational Hygiene Feb 1993This paper describes the approach of setting an occupational exposure limit for phosphamidon, an organophosphorus pesticide, in the workplace in China. Apart from a... (Review)
Review
This paper describes the approach of setting an occupational exposure limit for phosphamidon, an organophosphorus pesticide, in the workplace in China. Apart from a general review of the literature relating to various toxicological studies, special emphasis has been placed on the results of a systematic occupational health survey on the workers exposed to phosphamidon. As a result of the survey, together with the literature review, a 'maximum allowable concentration' (MAC) for phosphamidon in the air of workplace is suggested as 0.02 mg m-3 but on the condition that the route of skin entry be blocked effectively. In addition, based on the description of the standard-setting process in China, a comparison has been made to the current U.K. approach.
Topics: China; Maximum Allowable Concentration; Occupational Exposure; Phosphamidon; Workplace
PubMed: 8460880
DOI: 10.1093/annhyg/37.1.89 -
Brazilian Journal of Medical and... Sep 2008The effect of N-acetylcysteine, a thiolic antioxidant, on attenuation of phosphamidon-induced oxidative stress and immune dysfunction was evaluated in adult male Wistar...
The effect of N-acetylcysteine, a thiolic antioxidant, on attenuation of phosphamidon-induced oxidative stress and immune dysfunction was evaluated in adult male Wistar rats weighing 200-250 g. Rats were divided into four groups, 8 animals/group, and treated with phosphamidon, N-acetylcysteine or the combination of both for 28 days. Oral administration of phosphamidon (1.74 mg/kg), an organophosphate insecticide, increased serum malondialdehyde (3.83 +/- 0.18 vs 2.91 +/- 0.24 nmol/mL; P < 0.05) and decreased erythrocyte superoxide dismutase (567.8 +/- 24.36 vs 749.16 +/- 102.61 U/gHb; P < 0.05), catalase activity (1.86 +/- 0.18 vs 2.43 +/- 0.08 U/gHb; P < 0.05) and whole blood glutathione levels (1.25 +/- 0.21 vs 2.28 +/- 0.08 mg/gHb; P < 0.05) showing phosphamidon-induced oxidative stress. Phosphamidon exposure markedly suppressed humoral immune response as assessed by antibody titer to ovalbumin (4.71 +/- 0.51 vs 8.00 +/- 0.12 -log(2); P < 0.05), and cell-mediated immune response as assessed by leukocyte migration inhibition (25.24 +/- 1.04 vs 70.8 +/- 1.09%; P < 0.05) and macrophage migration inhibition (20.38 +/- 0.99 vs 67.16 +/- 5.30%; P < 0.05) response. Phosphamidon exposure decreased IFN-small u, Cyrillic levels (40.7 +/- 3.21 vs 55.84 +/- 3.02 pg/mL; P < 0.05) suggesting a profound effect of phosphamidon on cell-mediated immune response. A phosphamidon-induced increase in TNF-alpha level (64.19 +/- 6.0 vs 23.16 +/- 4.0 pg/mL; P < 0.05) suggests a contributory role of immunocytes in oxidative stress. Co-administration of N-acetylcysteine (3.5 mmol/kg, orally) with phosphamidon attenuated the adverse effects of phosphamidon. These findings suggest that oral N-acetylcysteine treatment exerts protective effect and attenuates free radical injury and immune dysfunction caused by subchronic phosphamidon exposure.
Topics: Acetylcysteine; Animals; Antibody Formation; Cell Migration Assays, Leukocyte; Free Radical Scavengers; Glutathione; Immunity, Cellular; Insecticides; Interferon-gamma; Male; Malondialdehyde; Ovalbumin; Oxidative Stress; Phosphamidon; Rats; Rats, Wistar; Superoxide Dismutase; Tumor Necrosis Factor-alpha
PubMed: 18820765
DOI: 10.1590/s0100-879x2008000900004 -
Journal of Biochemical and Molecular... 2010The molecular mechanism for noncholinergic toxicity of phosphamidon, an extensively used organophosphate pesticide, is still not clear. The aim of the present study is...
The molecular mechanism for noncholinergic toxicity of phosphamidon, an extensively used organophosphate pesticide, is still not clear. The aim of the present study is to find the possible molecular mechanism of this pesticide to induce apoptosis and the role of different drugs for attenuation of such effects. Human peripheral blood mononuclear cells (PBMC) were incubated with increasing concentrations of phosphamidon (0-20 μM) for 6-24 h. The MTT assay reveals that phosphamidon induces cytotoxicity in a dose-dependent manner. Cellular glutathione (GSH) is depleted in a dose-dependent manner from 55% to 70% at concentrations between 10 and 20 μM. The percentage of cells that bind to Annexin-V, which is a representative of cells either undergoing apoptosis or necrosis during 24 h incubation, increases in a dose-dependent manner. Above 5 μM, significant necrosis of cells was observed. DNA fragmentation assay revealed that at low concentration of phosphamidon (1 μM), no appreciable change in DNA fragmentation was seen; however, distinct fragmentation was observed beyond 2.5 μM. Phosphamidon was found to cause significant depletion of GSH, which correlates well with the percentage of cells undergoing apoptosis. An increasing trend in levels of cytochrome c was observed with increasing concentration of phosphamidon, indicating that the apoptotic effect of phosphamidon is mediated through cytochrome c release. Coadministration of the antioxidants N-acetylcysteine and curcumin attenuated phosphamidon-induced apoptosis. This further supports our hypothesis that oxidative stress, as indicated by GSH depletion, results in the induction of apoptosis by release of cytochrome c.
Topics: Acetylcysteine; Annexin A5; Antioxidants; Apoptosis; Cell Survival; Coloring Agents; Curcumin; Cytochromes c; DNA Fragmentation; Dose-Response Relationship, Drug; Glutathione; Humans; Insecticides; Leukocytes, Mononuclear; Necrosis; Oxidative Stress; Phosphamidon; Protective Agents; Reproducibility of Results; Tetrazolium Salts; Thiazoles; Time Factors
PubMed: 20979154
DOI: 10.1002/jbt.20337 -
Human & Experimental Toxicology Oct 2011Progesterone (a neurosteroid) is an important modulator of the nervous system functioning. Organophosphorus pesticides like phosphamidon have been shown to adversely...
Progesterone (a neurosteroid) is an important modulator of the nervous system functioning. Organophosphorus pesticides like phosphamidon have been shown to adversely affect memory and induce oxidative stress on both acute and chronic exposure. The present study was therefore designed to investigate the effects of progesterone (PROG) on phosphamidon-induced modulation of cognitive function and oxidative stress in rats. Cognitive function was assessed using step-down latency (SDL) on a passive avoidance apparatus and transfer latency (TL) on an elevated plus maze. Oxidative stress was assessed by examining the levels of thiobarbituric acid reactive species (TBARS) and non-protein thiols (NP-SH) in isolated homogenized whole brain samples. The results showed a significant reduction in SDL and prolongation of TL in the phosphamidon (1.74 mg/kg/d; p.o.) treated group at weeks 6 and 8 as compared to the control group. Two weeks treatment with PROG (15 mg/kg/d; i.p.) antagonized the effect of phosphamidon on SDL as well as TL. Phosphamidon alone produced a significant increase in the brain TBARS levels and decrease in the brain NP-SH levels. Treatment with PROG (15 mg/kg/d; i.p.) attenuated the effect of phosphamidon on oxidative stress. Together, the results showed that progesterone attenuated the cognitive dysfunction and increased oxidative stress induced by phosphamidon in the brain.
Topics: Animals; Avoidance Learning; Brain; Cognition Disorders; Insecticides; Male; Maze Learning; Memory; Oxidative Stress; Phosphamidon; Progesterone; Progestins; Rats; Rats, Wistar; Sulfhydryl Compounds; Thiobarbituric Acid Reactive Substances
PubMed: 21257640
DOI: 10.1177/0960327110396522 -
Toxicology and Applied Pharmacology Sep 1991Phosphamidon (2-chloro-3-(diethylamino)-1-methyl-3-oxopropanyldimethyl phosphate) is widely used in agriculture as an organophosphate insecticide. It is a water-soluble...
Phosphamidon (2-chloro-3-(diethylamino)-1-methyl-3-oxopropanyldimethyl phosphate) is widely used in agriculture as an organophosphate insecticide. It is a water-soluble cholinesterase inhibitor whose estimated rat LD50 is 9.2 mg/kg, ip. Mechanical and electrophysiologic direct effects of phosphamidon were studied in an isolated working rat heart model. Phosphamidon caused a positive inotropic effect, as indicated by increased maximum time derivative of left ventricular pressure and increased cardiac output. Stroke work and total pressure-volume area increased in a dose-dependent manner following perfusion with phosphamidon. Phosphamidon had in this preparation a biphasic effect on heart rate: at 10(-6) M concentration, heart rate increased, but at higher concentrations (10(-4)-10(-3) M) heart rate decreased significantly. High concentrations of phosphamidon caused a significant prolongation of the Q-T interval. We conclude that phosphamidon has potent cardiotoxic effects, both mechanical and electrophysiologic, on the isolated rat heart.
Topics: Animals; Cardiac Output; Electrophysiology; Heart; Heart Rate; Male; Myocardial Contraction; Perfusion; Phosphamidon; Rats; Rats, Inbred Strains
PubMed: 1949011
DOI: 10.1016/0041-008x(91)90044-f -
Pharmacology & Toxicology Jun 1992We studied the effects of phosphamidon (an organophosphate compound), obidoxime (a cholinesterase reactivator), and their combination, phosphamidon/obidoxime (PD/OB) on...
We studied the effects of phosphamidon (an organophosphate compound), obidoxime (a cholinesterase reactivator), and their combination, phosphamidon/obidoxime (PD/OB) on cardiac cycle length (RR), QT interval, and on QT-RR relationship of isolated rat heart. Cardiac cycle length did not change significantly following perfusion with phosphamidon or obidoxime alone; however, following perfusion with PD/OB, RR significantly increased at high concentrations (10(-3) M) of both drugs. The QT interval lengthened by 5% following perfusion with phosphamidon, did not change following perfusion with obidoxime, and increased by 10% following perfusion with PD/OB. The QT-RR relationship without drugs was positive and linear. Following perfusion with phosphamidon alone, the slope of the relationship decreased significantly, while perfusion with obidoxime alone did not change the QT-RR relationship. Perfusion with PD/OB at low concentrations decreased the slope of the relationship; however, at the highest concentration (10(-3) M) the QT-RR relationship was inverted and became negative. Ventricular arrhythmias as premature ventricular beats, or bigeminies, were noted with increasing frequency following perfusion with increasing doses of phosphamidon. Perfusion with obidoxime did not cause arrhythmias, whereas perfusion with PD/OB caused premature ventricular beats, bigeminies, and ventricular tachycardias at high doses. We suggest that obidoxime modulates the direct effects of phosphamidon on the cardiac repolarization process. PD/OB at high concentrations invert the normal depolarization-repolarization coupling and may therefore potentiate arrhythmias.
Topics: Animals; Drug Therapy, Combination; Electrocardiography; Electrophysiology; Heart; In Vitro Techniques; Male; Obidoxime Chloride; Perfusion; Phosphamidon; Rats; Rats, Sprague-Dawley; Ventricular Function
PubMed: 1438017
DOI: 10.1111/j.1600-0773.1992.tb00497.x -
Indian Journal of Experimental Biology Sep 2015Organophosphorus (OP) compounds commonly used as pesticides in agriculture cause serious health problems to living beings. The present study enumerates the ameliorating...
Organophosphorus (OP) compounds commonly used as pesticides in agriculture cause serious health problems to living beings. The present study enumerates the ameliorating effect of ginger extract (GE) against phosphamidon (PHO, an organophosphorus insecticide) induced hepatotoxicity. GE was prepared from dried ginger and characterized for compound profile and antioxidant activity. Eight groups of albino rats (n = 6) were treated with 1/5th lethal dose of PHO for 5-20 days. Out of the treated 8 groups, 4 were simultaneously fed with GE (1 mg/kg body wt.) along with PHO. Alterations in the levels of hepatocellular oxidative stress (OS) markers in the treated groups indicated an enhanced generation of reactive oxygen species (ROS) and oxidative stress (OS). Upregulation of apoptotic markers, DNA fragmentation and appearance of apoptotic nuclei suggested induction of apoptosis in the liver cell that was found to be attenuated after GE treatment. Moreover, no toxicity and mortality was observed up to 100 mg/kg dose of GE for 30 days in the rat model studied. Thus, GE can be considered as an effective, economical and safe extract to circumvent PHO-induced hepatotoxicity.
Topics: Animals; Apoptosis; Chemical and Drug Induced Liver Injury; DNA Fragmentation; Dose-Response Relationship, Drug; Drug Evaluation, Preclinical; Ethanol; Zingiber officinale; Hepatocytes; Insecticides; Lipid Peroxidation; Liver Function Tests; Male; Mutagenicity Tests; Organophosphate Poisoning; Oxidative Stress; Phosphamidon; Phytotherapy; Plant Extracts; Plant Roots; Polyphenols; Random Allocation; Rats; Rats, Wistar; Reactive Oxygen Species; Solvents; Ultrafiltration
PubMed: 26548077
DOI: No ID Found -
Environmental Pollution (Barking, Essex... 1989Thirty-day-old seedlings of rice plants (IR-20 variety) from the nursery were transplanted into experimental plots and after 52 days were sprayed with phosphamidon...
Thirty-day-old seedlings of rice plants (IR-20 variety) from the nursery were transplanted into experimental plots and after 52 days were sprayed with phosphamidon (Dimecron 85% EC) at two dose-rates (0.38 kg a.i. ha(-1) and 0.76 kg a.i. ha(-1)). Residues of phosphamidon in the plant, soil and water were analysed by GLC, at various time intervals, and were found to decrease steadily up to 15 days. A second application of the pesticide was made on day 113 and grains harvested on day 138. The residue level in the plants was 0.12 microg g(-1) and in the grains 0.04 microg g(-1) with the high dose. This is slightly below the EPA prescribed tolerance level of 0.05 microg g(-1). The residues in both soil and water were very low, 24 h after spraying.
PubMed: 15092362
DOI: 10.1016/0269-7491(89)90243-1