Deltamethrin toxicity

Gonzalez-Murua, C., A. Munoz-Rueda, F. Hernando, and M. Sanchez-Diaz. 1985. Effect of atrazine and methabenzthiazuron on oxygen evolution and cell growth of Chlorella pyrenoidosa. Weed Res. 25 61-66. Gorge, G. and R. Nagel. 1990. Toxicity of lindane, atrazine, and deltamethrin to early life stages of zebrafish (Brachydanio rerio). Ecotoxicol. Environ. Safety 20 246-255. 

As previously mentioned, early in vivo acute toxicity studies indicated that the action of Type II pyrethroids on the nervous system was different from that of the Type I pyrethroids. Deltamethrin decreased the acetylcholine content of the cerebellum, whereas DDT, a well-established voltage-sensitive sodium channel agonist, and cismethrin, caused no significant reduction [2]. 

Issam C, Samir H, Zohra H et al (2009) Toxic responses to deltamethrin low doses on gonads, sex hormones and lipoperoxidation in male rats following subcutaneous treatments. J Toxicol Sci 34 663-670... 

The age dependence of deltamethrin metabolism in vitro, and toxic signs and blood levels of the neurotoxic parent compound following administration of deltamethrin at 10 mg/kg p.o. was investigated [35]. Metabolism was quantified in vitro by monitoring the disappearance of the parent compound from plasma (via CESs) and liver microsomes (via CESs and CYPs) obtained from 10-, 21-, and 40-day-old male SD rats. Mean intrinsic clearances (Vmax/Km) in these respective... 

Day KE (1991) Effects of dissolved organic carbon on accumulation and acute toxicity of fenvalerate, Deltamethrin and cyhalothrin to Daphnia magna (Straus). Environ Toxicol Chem 10 91-101... 

Environmental Impacts Deltamethrin is highly toxic to insects, including non-target species. ... 

Table 2 shows the relative toxicities of leading pyrethroids when applied topically to houseflies, deltamethrin being one of the most potent pyrethroids commercialised. More recent product introductions have been flumethrin and cyhalothrin. 1998 global sales of pyrethroids were 190m, they are particularly attractive products for tick control giving rapid clean-up and persistent efficacy. 

Deltamethrin is toxic to bees. Fish and crustaceans are extremely sensitive to pyrethroid compounds in laboratory settings. However, various factors (e.g.,... 

Pyrethroids may conveniently be classified into two groups based on the chemical structure and toxic action (1 -Z8). Type I pyrethroids do not possess an alpha-cyano group and include many conventional ones such as allethrin, tetramethrin, phenothrin and permethrin. Type II pyrethroids possess a cyano group at the a position and include cyphenothrin, cypermethrin, deltamethrin and fenvalerate. 

Pyrethroid insecticides (deltamethrin, NRDC 157, cismethrin), DDT analogs ( p,j> -DDT, (>,j> -DDT, methoxychlor, EDO), and a DDT-pyrethroid hybrid compound (GH401) enhanced veratridine-dependent sodium uptake by mouse brain synaptosomes The effectiveness of these compounds in the sodium uptake assay was in good agreement with their acute mammalian toxicities. , -DDT also enhanced veratridine-dependent sodium uptake by fish brain synaptosomes These findings demonstrate the utility of ion flux assays to study interactions of insecticides with sodium channels in the central nervous system and to explore species differences in insecticide target site sensitivity ... 

We explored the potency of pyrethroid action in this system using deltamethrin, NRDC 157 (3-phenoxybenzyl [lR,cis]-3-( 2,2-dibromovinyl)-2,2-dimethylcyclopropanecarboxylate the non-cyano analog of deltamethrin), and their nontoxic enantiomers as test compounds ( Table II). Deltamethrin produced half-maximal enhancement of veratridine-dependent activation at 25 nM, whereas NRDC 157 was approximately tenfold less potent and the nontoxic enantiomers were inactive. These findings demonstrate that the effect of pyrethroids on mouse brain sodium channels is both potent and stereospecific for toxic isomers. The relative potencies of deltamethrin and NRDC 157 in this assay also agree well with their... 

Table II. Effects on Sodium Channel Activation and Acute Intracerebral Toxicity of Deltamethrin, NRDC 157, and Their Enantiomers in Mice3...

Figure 3. Toxicity of deltamethrin to the susceptible Canton-S and temperature-sensitive napts strains of Drosophila melanogaster. Adult females were tested in a surface contact bioassay at three dosages of deltamethrin applied to 50 ml Ehrlenmeyer flasks. A dosage of 0.05 p.g/flask was near the LD50 for Canton-S, but caused no mortality in the napts strain. At lOx and lOOx higher dosages, however, the toxicities were the same in both strains. For each treatment group shown n = 60.

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