Diazinon effects

Sastry, K.V. and K. Sharma. 1980. Diazinon effect on the activities of brain enzymes from Ophiocephalus (Channa) punctatus. Bull. Environ. Contam. Toxicol. 24 326-332. 

Muggleton, N.G., Smith, A.J., and Scott, E.A.M. et al. (2005). A long term study of the effects of diazinon on steep, the electrocorticogram and cognitive behaviour in common marmosets. Journal of Psychopharmacology 19, 455 66. 

Pre-exposure to the organophosphate diazinon at exposures half the LC50 values increased the LC50 value by a factor of about five for guppy (Poecilia reticulata), but had no effect on the value for zebra fish (Brachydanio rerio). This was consistent with the observation that during pre-exposure of guppy there was a marked inhibition in the synthesis of the toxic metabolites diazoxon and pyrimidinol, whereas this did not occur with zebra fish in which the toxicity was mediated primarily by the parent compound (Keizer et al. 1993). 

The effects of water temperature and pesticide concentration on pesticide recoveries were tested by Moye et al The pesticides included alachlor, atrazine, bromacil, chlorothalonil, chloropyrifos, diazinon, endosulfan, simazine and trifluralin. Temperatures of 5,25,45 and 65 °C were tested and concentrations of 0.1,1.0 and 10 pgL were used. Water temperature had a pronounced effect on the recoveries whereas the concentration did not seem to have as great an effect. 

Even though all OP insecticides have a common mechanism of action, differences occur among individual compounds. OP insecticides can be grouped into direct and indirect ACHE inhibitors. Direct inhibitors are effective without any metabolic modification, while indirect inhibitors require biotransformation to be effective. Moreover, some OP pesticides inhibit ACHE more than PCHE, while others do the opposite. For example, malathion, diazinon, and dichlorvos are earlier inhibitors of PCHE than of ACHE. In these cases, PCHE is a more sensitive indicator of exposure, even though it is not correlated with symptoms or signs of toxicity. 

Lowest tested diazinon concentrations that in medium produced significant nonlethal biological effects to aquatic organisms... 

Alam, M.K. and O.E. Maughan. 1992. The effect of malathion, diazinon, and various concentrations of zinc, copper, nickel, lead, iron, and mercury on fish. Biol. Trace Elem. Res. 34 225-236. 

Modified from Hoffman, D.J. and W.C. Eastin, Jr. 1981. Effects of malathion, diazinon, and parathion on mallard embryo development and cholinesterase activity. Environ. Res. 26 472-485. 

Table 16.7 Lowest Tested Diazinon Concentrations in Medium that Produced Significant Nonlethal Biological Effects to Aquatic Organisms...

Diazinon exerts its toxic effects by binding to the neuronal enzyme acetylcholinesterase (AChE) for long periods after exposure. Diazinon, in turn, is converted to diazoxon, which has a higher affinity for AChE (and thus greater toxicity) than the parent compound. There is a latent period in... 

Table 16.8 Sublethal Effects of Diazinon in Selected Mammals... 

Sprayed with 100 mg/L diazinon solutions 4 min Effective lice control for 3 weeks, partial protection for 8.6 weeks 13... 

Uyeki 1981 Chen etal. 1982). Diazoxon, an oxygen analog of diazinon, did produce SCE at 304 mg/kg, but was 3 to 10 times less effective than oxygen analogues of other organophosphorus compounds screened (Nishio and Uyeki 1981). 

---