Methyl parathion insecticide toxicity

Piperonyl butoxide, a common potentiator of insecticide effects that inhibits microsomal enzymes, antagonized the toxic effects of methyl parathion in mice (Mirer et al. 1977). 

Structures of toxicants that can affect pulse rate. Methyl parathion, a commonly used plant insecticide, can cause bradycardia. Imiprimine hydrochloride, a tricyclic antidepressant, can cause either tachycardia or arrhythmia. 

Bee hazard of methyl parathion, 11(6-67 reduction by adjuvants, 11(6-67 Bee hives, insecticide contamination, 1i(2-ilil Bee toxicity, insecticide-treated fields, 1i(i(-i(6... 

Induction of glutathione S-transferases by phenobarbital in houseflies provides some protection against the toxicity of methyl parathion, methyl paraoxon, azinphosmethyl, and methidathion. Similarly, induction of glutathione S-transferase by host plants in fall armyworm larvae protects the larvae against organophosphate insecticides. Larvae fed... 

The most important inhibitors of CarbEs are organo-phosphorus insecticides (malathion, parathion, para-oxon, methyl parathion, EPN, and others), nerve agents (DFP, soman, sarin, tabun, and VX) and carbamate insecticides (carbofuran, carbaryl, aldicarb, propoxur, oxamyl, methomyl, and others). Organo-phosphorus toxicants inhibit CarbEs irreversibly by phosphorylation and carbamates inhibit CarbEs reversibly by carbamylation similar to the basic mechanism (i.e., acylation of the active site) ... 

Decreased sensitivity to insecticides in resistant strains of mosquitofish from Belzoni, Mississippi is partly based on their ability to metabolize the toxicant rapidly. Resistant strains converted aldrin to dieldrin and water-soluble components to a greater extent than sensitive strains89. Resistant strains also had higher activities of methyl-parathion dearylation which appear to be catalyzed by the higher levels of CYP in this strain15. 

Chronic toxicity of organophosphates may be discussed under four different areas carcinogenicity, delayed neurotoxicity, experimental myopathy, and, in humans, psychiatric disorders. In 1983, the IARC (International Agency for Research on Cancer) evaluated the carcinogenic potential of, among other pesticides, five organophosphate insecticides/acaricides (malathion, methyl parathion, parathion,... 

OP insecticide-induced intermediate syndrome (IMS) was reported for the first time in human patients in Sri Lanka in 1987 (Senanayake and Karalliede, 1987). Since then, this syndrome has been diagnosed in OP-poisoned patients in South Africa (1989), Turkey (1990), Belgium (1992), the United States (1992), Venezuela (1998), France (2000), and elsewhere. IMS is usually observed in individuals who have ingested a massive dose of an OP insecticide either accidentally or in a suicide attempt. IMS is clearly a separate clinical entity from acute toxicity and delayed neuropathy. A similar syndrome has also been observed in dogs and cats poisoned maliciously or accidentally with massive dosc.s of certain OPs. OPs that are known to cause IMS include bromophos, chlorpyrifos, diazinon, dicrotophos, dimethoatc, fenthion, malathion, merphos, methamidophos, methyl parathion, monocrotophos, omethoate, parathion, phosmet, and trichlorfon. These compounds and IMS are discussed further in Chapter 26. 

Karanth, S Liu, J., Olivier, K, Jr, and Pope, C. (2004), Interactive toxicity of the organopho.sphorus insecticides chlorpyrifos and methyl parathion in adult rats. Toxicol. Appl Phammeoi. 196, 18.3-190. 

Convention are no longer to be produced in China for example, the five highly toxic OP insecticides (methamidofos, parathion, methyl parathion, monocrotophos, and phosphamidon) are prohibited from use on fruits and vegetables. They vill be forbidden to be produced, distributed, and used on January 1, 2007. 

Although no data were available on the effects of fanphur in aquatic ecosystems, there is a substantial data base on other organophos-phorus insecticides. For example, methyl parathion (0,0-dimethyl 0-(/7-nitrophenyl) phosphorothioate), another phosphorothioate organophosphoms insecticide, had LC50 (96 h) values for bluegills and rainbow trout that were similar to those of famphur 5.7 mg/L and 2.7 mg/L, respectively. But exposure for 96 h is not sufficient to satisfactorily evaluate the aquatic toxicity of organophos-phorus insecticides. The mortality of adult... 

Parathion methyl 6-24 300-420 Rat, 2-year diet, NOAEL 2-mg/kg diet Rat embriotoxicity and feto-toxicity at 1 mg/kg. Some test have demonstrated certain evidence of geno-toxicity. 6.6-7.6 2.7-6.9 0.291 Insecticide, acaricide... 

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