Organochlorines cyclodienes

Wigfield YY, Grant R. 1992. Evaluation of an immunoassay kit for the detection of certain organochlorine (cyclodiene) pesticide residues in apple, tomato, and lettuce. Bull Environ Contain Toxicol 49 342-347. 

Chemical/Pharmaceutical/Other Class Synthetic organochlorine cyclodiene insecticide... 

As with other organochlorine cyclodiene compounds, chlordane is metabolized mainly by the liver microsomal cytochrome P-450 system. Several metabolites are produced including chlordene chlor-ohydrin, monohydroxylated dihydrochlordene, oxy-chlordane, and relatively smaller but similar amounts of 1,2-dichlorochlordene, l-hydroxy-2-chloro-chlordene, l-hydroxy-2-chloro-2,3-epoxychlordene,... 

Animal toxicity with endrin is similar to that of other organochlorine cyclodiene insecticides. The oral LD50 in rats is 7- 3 mg kg while in mice it is... 

The detrimental effect of organochlorine pesticides on reproductive success in birds of prey is well established following the crash of some populations during the 1950s and 1960s. Links have been established with the DDT metabolite, DDE, the cyclodiene pesticides and Although many raptor species... 

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). 

Cyclodienes A group of organochlorine (OC) insecticides, some of which are highly toxic and persistent (e.g., aldrin, dieldrin, and heptachlor). 

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). 

A second organochlorine pesticide, heptachlor (HEP), a chlorinated cyclodiene that was used primarily as an agricultural and domestic insecticide, was evaluated for its potential to suppress the immune system of rats. Rats were exposed to HEP pre-and postnatally, as described above for MXC. The IgM antibody response to SRBCs was suppressed at all doses in males but not females at 8 weeks of age. At 26 weeks of age, the IgG anti-SRBC response was suppressed in all of the HEP-exposed males, but not females.131... 

Following acute exposure to cyclodiene organochlorine pesticides, seizures and respiratory depression may occur (Ellenhom 1988 Proctor et al. 1988). Benzodiazepines (e.g., diazepam or lorazepam) or other anticonvulsant medications (e.g., phenobarbital) have been commonly used to control seizures (Ford 1993). Organochlorines may sensitize the myocardium to the proarrhythmic effects of adrenergic amines, potentially resulting in initiation of ventricular fibrillation (TOMES 1994). 

Cyclodiene pesticides, of which endrin and its oxidized analogs are representative, can also be estimated by receptor-assay technique. Cyclodiene pesticides exert their mode of action by altering central nervous system membrane ion transport. In work reported by Saleh et al. (1993), a labeled amino acid, GABA, that binds to the chloride channel receptor is displaced by endrin (and other similar molecules), and thus serves as an assay for these pesticides. The GABA receptor was shown to be a potentially useful biomarker for organochlorine pesticides such as lindane, toxaphene, endrin, chlordane, and others. The assay involves small quantities of blood (0.1 mL), and requires only that the plasma be separated from the... 

Chlordane (C HgClg) and Hentachlor (C gH Cly) belong to the family of bicyclic cyclodiene organochlorine insecticides discussed earlier (See under Aldrin). Both compounds are highly toxic, readily... 

Chlordane was introduced as an insecticide in 1945 and was the first cyclodiene insecticide that was used in agriculture (Eisler, 1990). It was the second most important organochlorine pesticide after toxaphene from 1976 to 1977 (Stansley Roscoe, 1999). It has been used on agricultural crops and extensively in the control of termites (Smith, 1991). Chlordane and heptachlor can be metabolized into two persistent (oxygenated) epoxides—oxychlordane and heptachlor epoxide—in mammals (Nomeir Hajjar, 1987) such that the two compounds are always measured together with chlordane and heptachlor. 

Australian health authorities and researchers have conducted a number of studies into organochlorine insecticide residues and human milk that span three decades of organochlorine use, from 1969 to the early 1990s. Early Australian studies of human milk contamination (e.g. HCB, DDT and metabolites, HCH isomers and cyclodienes) cover the period from 1969 to 1972 and include Western Australia (Stacey Thomas, 1975), New South Wales (Siyali, 1973), Victoria (Monheit Luke, 1990) and Queensland (Miller Fox, 1973). Total DDT was shown to occur in the parts per billion range (pg kg-1) in whole milk and in the parts per million range (mg kg-1) in milk fats. 

As seen from the structural formulas in Figure 16.4, the organochlorine insecticides are of intermediate molecular mass and contain at least one aromatic or nonaromatic ring. They can be placed in four major chemical classes. The first of these consists of the chloroethylene derivatives, of which DDT and methoxychlor are the prime examples. The second major class is composed of chlorinated cyclodiene compounds, including aldrin, dieldrin, and heptachlor. The most highly chlorinated members of this class, such as chloredecone, are manufactured from hexachlorocyclo-pentadiene (see Section 16.3). The benzene hexachloride stereoisomers make up a third class of organochlorine insecticides, and the third group, known collectively as toxaphene, constitutes a fourth. 

The cyclodiene group of organochlorines was introduced in 1948, starting with chlordane, then aldrin, dieldrin, endrin and toxaphene, and then heptachlor BHC was already available at the close of the war. The experience with housefly control in the Mediterranean countries was that DDT-resistance came in 2 years, and the substitution of BHC was followed by BHC-resistance a year... 

Cyclodiene organochlorine) C v GABA receptor-chloride channel... 

See a/so Carbon Monoxide Charcoal Chlorine Chlorine Dioxide Cyclodienes Diazepam Organochlorine Insecticides Phosgene Pollution, Soil Pollution, Water. 

Symptomatology is essentially the same as that described for organochlorine insecticides. In many cases, convulsions are the first sign of toxicity without the progression of nerve hyperactivity seen in other classes of organochlorine insecticides. More recently, evidence of endocrine disruption in both mammalian and other species has been accumulating for several cyclodiene pesticides including chlordane, aldrin, dieldrin, lindane, and endosulfan. 

Organochlorine insecticides may be divided into three broad groups dichlorodiphenylethanes, such as DDT and methoxychlor cyclodienes, such as chlor-dane and dieldrin and hexachlorocyclohexanes, such as lindane. Mirex and chlordecone, however, are organochlorine insecticides whose caged structures do not fit well into the previous groups. 

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