Phosphate organophosphate

Class Organophosphate Phosphate ester Phosphate ester... 

In the Organophosphate Phosphate Antiporter (OPA) family (2. A. 1.4), most members preferentially catalyze substrate substrate antiport, but they can also catalyze substrate H symport, and some preferentially seem to use a symport rather than an antiport mechanism. Also, in the Nitrate/ Nitrite Porter (NNP) family (2.A. 1.8), members of similar sequence can catalyze either uptake, efflux, or NO j NO exchange. Finally, members of the Organocation Transporter (OCT) family in animals (2.A.1.19) appear to be mechanistically promiscuous, catalyzing substrate uptake, export, exchange, and/or uniport. Sometimes the mechanism and substrate H stoichiometry depends on... 

Diethyl 0-(3-methyl-5-pyrazolyl) phosphate (722) and 0,0-diethyl 0-(3-methyl-5-pyrazolyl) phosphorothioate (723) were prepared in 1956 by Geigy and they act, as do all organophosphates in both insects and mammals, by irreversible inhibition of acetylcholinesterase in the cholinergic synapses. Interaction of acetylcholine with the postsyn-aptic receptor is therefore greatly potentiated. 0-Ethyl-5-n-propyl-0-(l-substituted pyrazol-4-yl)(thiono)thiolphosphoric acid esters have been patented as pesticides (82USP4315008). 

The secondary biological cycles stem from the crucial roles that phosphates and particularly organophosphates play in all life processes. Thus organophosphates are incorporated into the backbone structures of DNA and RNA which regulate the reproductive processes of cells, and they... 

A recent method to screen the urine for alkyl phosphates as an indicator of exposure to organophosphate insecticides shows that the method can be used to determine environmental exposure to a specific organophosphate pesticide. The method was found to be sensitive, identifying low levels of exposure to insecticides in the environment by quantitation of urinary phosphates (Davies and Peterson 1997). The test is limited in that it is only useful for assessing recent exposure, due to the short half-life of the organophosphate pesticides. 

Davies JE, Peterson JC. 1997. Surveillance of occupational, accidental, and incidental exposure to organophosphate pesticides using urine alkyl phosphate and phenolic metabolite measurements. Aim NY Acad Sci 837 257-268. 

Aryl phosphates and thiophosphates, and alkyl dithiophosphates are important agrochemicals, while phosphorofluoridates have been prepared as chemical warfare agents. Concern over the persistence and the biodegradability of organophosphate and organophosphorothioates, which are nsed as agrochemicals, has stimnlated stndies into their degradation. Considerable attention has been... 

Intermediate-duration inhalation exposures to aerosols of a few organophosphate ester hydraulic fluids (Durad MP280 and "triaryl phosphate ester") produced lethal neurotoxic effects in chickens and rabbits (MacEwen and Vemot 1983 Siegel 1965). Rats and hamsters appear to be less susceptible to the neurotoxic action of organophosphate esters tests of several organophosphate fluids produced no deaths in rats exposed to substantial aerosol concentrations. 

Following intermediate-duration exposure to organophosphate ester hydraulic fluids, reversible rapid respirations were observed in rabbits exposed to 2,000 mg/m3 of a triaryl phosphate hydraulic fluid (Cellulube 220) (Carpenter et al. 1959) and reddish nasal discharge (likely to be indicative of respiratory tract irritation) was observed in rats exposed to 100 mg/m3 of Skydrol 500B-4 (Healy et al. 1992 ... 

Organophosphate Ester Hydraulic Fluids. In a study of nonspecific monocyte esterase staining, humans who were exposed to aryl phosphates occupationally showed very slight esterase inhibition (Mandel et al. 1959). 

One study was located regarding neurological effects in humans after inhalation exposure to organophosphate ester hydraulic fluids. Workers in an aryl phosphate manufacturing plant were not found to have neurological deficits even with decades of potential exposure (Reade 1982). 

Intermediate-duration oral exposure to Durad 110 produced deaths in chickens associated with the delayed development of neuropathy at dosage levels of 4,000 mg/kg/day in a 28-day study and 90 mg/kg/day in a 90-day study (FMC 1986). At 100 mg/kg/day over a 13-week period, 2 of 12 male and 1 of 12 female rats died with exposure to tri- -butyl phosphate (Healy et al. 1995). Dietary administration of Pydraul 90E for 90 days providing daily doses of 50 mg/kg/day produced no chemical-related deaths in rats (Monsanto 1979). An organophosphate ester hydraulic fluid designated MIL-H-83306 also caused death in 4 of 4 rats exposed by gavage to 1,000 mg/kg over a 26-day period (Mattie et al. 1993). 

No gross or histological hepatic alterations were observed in rabbits exposed to <480 mg/kg/day or chickens exposed to up to 720 mg/kg/day, respectively, of Cellulube 220 for an acute duration (Carpenter et al. 1959). No hepatic effects were reported in rats exposed to 50 mg/kg/day of Pydraul 90E for an intermediate duration (Monsanto 1979). Several intermediate-exposure rat studies showed liver effects for organophosphate esters. Liver weight increases were shown for tributyl phosphate at 250 mg/kg/day (Laham et al. 1985 Oishi et al. 1982), trioctyl phosphate at 250 mg/kg/day (Oishi et al. 1982),... 

None of the calves of 10 cows showed clinical signs of neurotoxicity after the cows were orally exposed to an unknown quantity of a Fyrquel hydraulic fluid reclamation waste that according to the authors possibly contained tri-ort/20-cresyl phosphate (TOCP), and that was applied liberally to their backs one time as a treatment for ringworm (Julian et al. 1976). The cows were seen licking their backs and the backs of other cows thus, the cows were orally and dermally exposed to organophosphate ester hydraulic fluids. 

Johannsen and colleagues (1977) report dermal LD50 values for rabbits at levels of >3,700 mg/kg for a group of triaryl phosphates, >5,000 mg/kg for dibutyl phenyl phosphate, 5,000 mg/kg for both asymmetrical and symmetrical triaryls, and >3,100 mg/kg for tributyl phosphate. This study looked at structural activity relationships for the organophosphate esters. 

Organophosphate Ester Hydraulic Fluids. No change in the levels of leukocytes was observed in workers dermally exposed to triaryl phosphate hydraulic fluids for an intermediate duration (Baldridge et al. 1959). 

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