Insecticide cyclodiene

The older cyclodiene insecticides like aldrin, dieldrin, heptachlor, chlordane, endrin, and endosulfan act also as antagonists on the GABA channels. These substances still represent some problems as environmental pollutants because many of them are very stable in organisms, soil, and sediments. They all have a characteristic clumsy structure. Endosulfan was introduced in 1956 and is still in use, whereas the other compounds were introduced between 1948 and 1950. 

Note that dieldrin is an oxidation product of aldrin. Epoxides are usually rather unstable, being hydrolyzed to diols or split up to the enols (double bond and hydroxyl group). Dieldrin may be formed in soil and organisms from aldrin and is very stable. 

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Balasubramaniam E, Paul V, Jayakumar AR, et al. 1996. The effect of chronic cyclodiene insecticide treatment on some pharmacological actions of diazepam in rats. Environ Toxicol and Pharm(2) 141-146. 

Flodstrom S, Warngard L, Hemming H, et al. 1988. Tumor promotion related effects by the cyclodiene insecticide endosulfan studied in vitro and in vivo. Pharmacol Toxicol 62 230-235. 

Gant DB, Eldefrawi ME, Eldefrawi AT. 1987. Cyclodiene insecticides inhibit GABA receptor-regulated chloride transport. Toxicol Appl Pharmacol 88 313-321. 

Tumer KO, Syvanen M, Meizel S. 1997. The human acrosome reaction is highly sensitive to inhibition by cyclodiene insecticides. J Androl 18(6) 571-575. 

The organochlorine insecticides (henceforward OCs) can be divided into three main gronps, each of which will be discnssed separately in the sections that follow. These are (1) DDT and related componnds, (2) the cyclodiene insecticides, and (3) isomers of hexachlorocyclohexane (HCH Brooks 1974 Fignre 5.1). 

The cyclodiene insecticides aldrin, dieldrin, endrin, heptachlor, endosulfan, and others were introduced in the early 1950s. They were used to control a variety of pests, parasites, and, in developing countries, certain vectors of disease such as the tsetse fly. However, some of them (e.g., dieldrin) combined high toxicity to vertebrates with marked persistence and were soon found to have serious side effects in the field, notably in Western European countries where they were extensively used. During the 1960s, severe restrictions were placed on cyclodienes so that few uses remained by the 1980s. 

In one example (Lawrence and Casida 1984, Abalis et al. 1985) rat brain microsacs were used to test the action of cyclodiene insecticides such as dieldrin and endrin on the GABA receptors contained therein. The influx of radiolabeled CL into the microsacs via the pore channel of the receptor was inhibited by these chemicals. A similar assay was developed using microsacs from cockroach nerve. Assays with this preparation showed again the inhibitory effect of a cyclodiene (this time heptachlor epoxide) on CL influx. Also, that microsacs from cyclodiene resistant cockroaches were insensitive to the inhibitory effect of picrotoxinin, which binds to the same site on the GABA receptor (Kadous et al. 1983). 

Abalis, I.M., Eldefrawi, M.E., and Eldefrawi, A.T. (1985). High affinity stereospecific binding of cyclodiene insecticides and gamma HCH to GABA receptors in rat brain. Pesticide Biochemistry and Physiology, 24, 95-102. 

Walker, C.H. and Newton, 1. (1998). Effects of cyclodiene insecticides on the sparrowhawk in Britain—a reappraisal of the evidence. Ecotoxicology 7, 185-189. 

TR. Dombrowski, E.M. Thurman, and G.B. Mohrman, A first application of enzyme-linked immunosorbent assay for screening cyclodiene insecticides in ground water, in Environmental Immunochemical Methods, ed. J.M. Van Emon, C.L. Ger-lach, and J.C. Johnson, American Chemical Society, Washington, DC, pp. 148-154 (1996). 

L.H. Stanker, B. Watkins, M. Vanderlaan, R. Elhs, and J. Rajan, Analysis of heptachlor and related cyclodiene insecticides on food products, in Immunoassays for Trace Chemical Analysis, ed. M. Vanderlaan, L.H. Stanker, B.S. Watkins, and D.W. Roberts, American Chemical Society, Washington, DC, Chapter 12, pp. 108-123 (1991). 

Technical chlordane is a mixture of chlorinated hydrocarbons that has been used as an insecticide since its introduction in 1947. Chlordane was the first cyclodiene insecticide to be used in agriculture and was the second most important organochlorine insecticide in the United States in 1976/1977, behind toxaphene, with an estimated annual production of 9 million kg (Nomeir and Hajjar 1987). Chlordane is a leading insecticide in controlling termites, with about 1.2 million homes in the United States alone treated annually for this purpose (Nomeir and Hajjar 1987). 

Folmar LC. 1978. In vitro inhibition of rat brain ATPase, pNPPase, and ATP-32Pi exchange by chlorinated-diphenyl ethanes and cyclodiene insecticides. Bull Environ Contam Toxicol 19(4) 481-488. 

Matsumura F. 1985. Involvement of picrotoxinin receptor in the action of cyclodiene insecticides. Neurotoxicology 6(2) 139-164. 

Stanker LH, Watkins B, Vanderlaan M, et al. 1989. Analysis of heptachlor and related cyclodiene insecticides in food products. In Vanderlaan M, ed. ACS (American Chemical Society) Symposium Series, 451. Immunoassays for trace chemical analysis Monitoring toxic chemicals in humans, food and the environment Meeting, Honolulu, Hawaii, December 17-22. Washington, DC American Chemical Society, 108-123. 

Cyclodiene insecticides produce intense nerve excitation in both vertebrate and invertebrate species (Matsumura 1985 Matsumura and Tanaka 1984). It has been suggested that the biochemical mechanisms by which these chemicals induce hyperexcitation in the central nervous system are due to the release of neurotransmitters caused by the interactions of the insecticide with the picrotoxinin receptor. 

Abalis IM, Eldefrawi ME, Eldefrawi AT. 1985. High-affinity stereospecific binding of cyclodiene insecticides and y-hexachlorocyclohexane to y-aminobutyric acid receptors of rat brain. Pestic Biochem Physiol 24 95-102. 

Gillett JW, Chan TM. 1968. Cyclodiene insecticides as inducers, substrates, and inhibitors of microsomal epoxidation. J Agric Food Chem 16 590-593. 

Georgacakis, E. and Khan, M.A.Q. Toxicity of the photoisomers of cyclodiene insecticides to freshwater animals. Nature... 

Ivie, G.W. and Casida, J.E. Enhancement of photoalteration of cyclodiene insecticide chemical residues by rotenone. Science (Washington, DC), 167(3935) 1620-1622, 1970. 

Khan, M.A.Q., Feroz, M., and Sudershan, P. Metabolism of cyclodiene insecticides by fish, in Pesticide and Xenobiotic Metabolism in Aquatic Organisms, ACS Symposium Series 99 (Washington, DC American Chemical Society, 1979). 

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