|
Lindane Papers Bibliographical recordLeBras, S. (1995) Adenosine Energy Charge (AEC) for Asellus Aquaticus L. (Crustacea, Isopoda) after Lindane Contamination during a Period of 48 h. Rev. Sci. Eau 8 (4) : 493-503 [article in French] Original title: Variation de la charge énergetique en adenylate (CEA) d'Asellus Aquaticus L. (Crustace, Isopode) après une contamination pendant 48 h. par du lindane SummaryThe objective of this study was to evaluate the applicability of adenosine energy charge (AEC) as an indicator of sublethal pollutant contamination for an aquatic invertebrate Asellus aquaticus L. ( Crustacea, Isopoda ). This study was carried out under laboratory conditions. Asellus collected in natural ponds were acclimated in the laboratory during a minimum period of 15 days. Individuals between 3 and 7 mg in weight were selected and kept at 15°C for 24 hours before contamination with lindane. Contamination was performed in glass containers in 250 ml of water, and 1 ml of lindane acetone solution. Concentrations of 2, 4, 8 and 10 mg/l were tested. The experimental period was 48 hours. After cold-induced anesthesia, Asellus individuals were rapidly dried and then dipped into liquid nitrogen and ground to a powder at - 80°C. Extraction of adenylates was performed with dimethyl sulfoxide (DMSO). ADP and AMP were converted to ATP with pyruvate kinase and phospho-enol-pyruvate for ADP; pyruvate kinase, myokinase and phospho- enol-pyruvate for AMP. The concentrations of ATP, ADP and AMP were measured using a bioluminescence technique with a luminometer (LKB Wallac 1250). AEC, defined as the ratio between (ATP + 1/2 ADP) and (ATP + ADP + AMP) concentration, was then calculated. AEC values were 0.77, 0.79, 0.69, 0.65 and 0.72 respectively for control animals and for Asellus specimens exposed to 2, 4, 8 and 10 µg/l lindane. According to IANOVICI (1979), AEC values for Asellus contaminated with 4, 8 or 10 µg/l of lindane were representative of the perturbation of environmental conditions. Nevertheless, these values show that recovery is possible if environmental conditions return to normal. However statistically significant differences (ANOVA, p= 0.05) were noted only between control and 4 or 8 µg/l lindane contaminated Asellus. ATP concentrations were 0.1451, 0.1876, 0.1821, 0.2325 and 0.1570 µmol/mg respectively for control, 2, 4, 8 and 10 µg/l of lindane. No significant difference was noted between control and contamination, except for 8 mg/l of lindane ( p= 0.01 ). ADP concentrations were 0.0698, 0.0253, 0.1200, 0.2121 and 0.0679 mmol/mg respectively for control, 2, 4, 8 et 10 mg/l of lindane. Only the ADP concentration for 8 mg/l of lindane was significant of ADP accumulation (ANOVA, p=0.05 ). AMP concentrations were 0.0193, 0.0272, 0.0470, 0.1182 and 0.0416 mmol/mg respectively for control, 2, 4, 8 and 10 mg/l of lindane. The increase of AMP concentration for 8 mg/l of lindane was significant ( risk 0.05 ). Variations of the adenylate pool (ATP + ADP + AMP) were 0.2342, 0.2401, 0.3491, 0.5628 and 0.2665 mmol/mg respectively for control, 2, 4, 8 et 10 mg/l of lindane. The increase of the adenylate pool concentration for 4 and 8 mg/l of lindane was significant (p=0.05 ). It appeared that the decrease of AEC at lindane concentrations of 4 and 8 mg/l was indicative of the increase of the energetic cost and the metabolism, resulting from the hyperexcitability characteristically induced by this category of contaminant. At 10 mg/l of lindane, the AEC value was approximately equal to that of the control exposure. It appeared correlated to the decrease in metabolic activity and accompanying reduction energy expenditure in response to the paralytic phase of intoxication. Finally under laboratory conditions AEC values appeared to be indicative of sublethal contamination, for this species and this toxicant. However for acute exposures it does not appear that AEC is a very good indicator. Keywords: Asellus aquaticus, Adenosine energy charge (AEC), ATP, ADP, AMP, lindane. Author's address S Le Bras, CNRS - URA 1492, Laboratoire d'écologie et de zoologie, bâtiment 442, Université de Paris-Sud, 95405 Orsay Cedex, FRANCE http://www.rse.uquebec.ca/ang/vol8/v8n4a4.htm Hexachlorocyclohexane (Lindane). The name lindane is specifically the gamma isomer of 1,2,3,4,5,6 hexachlorocyclohexane (HCH). Lindane exists in two stable configurations in three dimensions, the so-called chair formations. These are depicted here.
Two stable configurations of gamma-HCH (lindane). Cyclohexane is not a planar structure like a benzene ring. It exists as a boat or chair arrangement which does not change the tetrahedral arrangement of any of the bonds connected to any one of the carbon atoms making up the cyclohexane backbone. The structures are provided above to explain the axial and equatorial designation given to the orientation of the chlorine atoms in the various isomers. The bonds nearest the viewer are darkened for perspective. One of the protons was left off of both figures in the back to keep the drawings from becoming too cluttered, and four of the carbons were numbered for reference. The chlorine atom attached to carbon 1 in the left figure is in the equatorial orientation, or pointing in the horizontal direction, the chlorine attached to carbon 2 points "up" or in the axial direction, the chlorine on carbons 3 and 4 are also pointing "up" or in the axial direction. You will note that on around the cyclohexane ring, the remaining two chlorines are equatorial. This configuration is referred to as aaaeee because three chlorines next to one another are pointing in the same direction, "up" (axial) while the remaining three chlorines are pointing "out" (equatorial). Now consider what happens when the molecule flips to its other stable configuration shown in the figure on the right. In this figure the carbon atoms are still numbered for identification. Notice that the three chlorine atoms that were axial are now equatorial and the three that were equatorial are now axial. In other words the configuration switched from aaaeee to eeeaaa. Indeed, no matter which direction the cyclohexane ring bent, the configuration will still come up aaaeee. As shown by the table enclosed below, six isomers of HCH have been identified and their properties measured. Structure and biological activity of HCH analogs. Isomer m.p. % in tech. orient. activity % inhibition DHPTx binding alpha 157 67-70% aaeeee weak excit. 21.4 beta 297 5-6 eeeeee weak depress. 15.3 gamma 112 13 aaaeee strong excit. 91.0 delta 130 6 aeeaee stong depress. 55.0 epsilon 219 trace aeeeee inactive --- nu 90 trace aeaaee inactive --- Taken from Matsumura (1985). Only one of the isomers shown has significant insecticidal properties, the gamma isomer of lindane. This implies that the three dimensional structure of the compound is important in toxicity. For a number of years the mode of action of lindane was unknown. Then in 1979, the connection was made between lindane, cyclodienes, toxaphene and picrotoxin. To undestand this connection, picrotoxin will be described next along with the final entry in the table above. http://wcb.ucr.edu/wcb/schools/CNAS/entm/tmiller/1/modules/page27.html LeBras, S. (1995) Adenosine Energy Charge (AEC) for Asellus Aquaticus L. (Crustacea, Isopoda) after Lindane Contamination during a Period of 48 h. Rev. Sci. Eau 8 (4) : 493-503 [article in French] Original title: Variation de la charge énergetique en adenylate (CEA) d'Asellus Aquaticus L. (Crustace, Isopode) après une contamination pendant 48 h. par du lindane http://www.rse.uquebec.ca/ang/vol8/v8n4a4.htm Journal
of Toxicology and Environmental Health: Part A
cis-Dehydrochlorination of Lindane by Human and Rat Liver Microsomes. J. F. Fitzloff, J. C. Pan, K. Stein, and J. P. Portig. The Fifth International Congress of Pesticide Chemistry, Kyoto, Japan, Abstract Ve-5, August 1982. Epoxidation of the Lindane Metabolite, beta-PCCH (346/5-pentachlorocyclohexene) by Human and Rat Liver Microsomes. J. F. Fitzloff and J. C. Pan. First International Symposium on Foreign Compound Metabolism, West Palm Beach, Florida, November 1983. Metabolic Profile of Lindane Given Dermally, Orally or Intraperitoneally to Rats. J. F. Fitzloff and J. C. Pan. 39th National Meeting of Academy of Pharmaceutical Sciences, Minneapolis, MN, October 1985. Synthesis and Steriochemical Aspects of Lindane Metabolite: 2,3,4,5,6-pentachlorocyclohex-3-enol. J. C. Pan and J. F. Fitzloff. 190th American Chemical Society Annual Meeting, Chicago, IL, September 1985. http://www.swri.edu/3pubs/papers/d01/01pres.htm 9204-141. Gopalaswamy U V, Nair C K K (Rad Bio Biochem Div, Bhabha Atom Res Cent, Trombay, Bombay 400085). DNA binding and mutagenicity of lindane and its metabolites. Bull Environ Contam Taxico, 49 (2) (1992), 300-305 [ 22 Ref]. The genotoxic potential of lindane and its metabolites HCB and PCP was investigated by determining the capacity of these compounds to bind DNA in vitro and in vivo. The present studies have provided evidence that lindane and its metabolites bind co-valently to DNA and possess the characteristics of a genotoxic agent. The metabolism of lindane in mammals involves the formation of oleinlns and a subsequent epoxidation. The toxicity of halogenated hydrocarbons could arise from irreversible binding of the epoxide intermediates to cellular constituents such as DNA or membranes.
http://everest.ento.vt.edu/~mullins/pestus2000/Lectures/Lecture11.html Similar challenges confound identifying sources of HCH, which is one of the
most widely used insecticides in the world (2, 14).
The technical mixture contains 60-70% α-HCH,
5-12% http://pubs.acs.org/hotartcl/est/99/may/using.html Lagadic, L., A. Cuany, J. B. Bergé and M. Echaubard. 1993. Purification and partial characterization of glutathione S-tranferases from insecticide-resistant and lindane-induced susceptible Spodoptera littoralis (Boisd.) larvae. Insect Biochem. Mol. Biol. 23:467-474. #0e6d68 The Fungus among Us: Use of White Rot Fungi to Biodegrade Environmental Pollutants Mechanisms of Biodegradation The first published report on the degradation of chemicals by white rot fungi demonstrated that these fungi degrade DDT, PCB, Lindane, dioxin, and benzo[a]-pyrene. That initial publication not only demonstrated the nonspecificity of the fungus but also showed its ability to oxidize highly chlorinated chemicals. Such highly chlorinated chemicals are electron deficient due to the high electronegativity of the chlorine. These chemicals must therefore be reduced before they can be oxidized. White rot fungus synthesizes and secretes a substrate for its own peroxidase enzymes: veratryl alcohol (3,4-dimethoxybenzyl alcohol). The partially oxidized veratryl alcohol (the cation free radical) then oxidizes other chemicals that are not directly oxidized by the peroxidase enzymes. To complete further degradation, the fungus produces organic acids that also inhibit veratryl alcohol oxidation. Why would the fungus produce a substrate and an inhibitor of its own enzymes? Further research demonstrated that oxalate, the major organic acid synthesized by white rot fungi, is also an excellent inhibitor of lignin peroxidases. Oxalate is easily oxidized to carbon dioxide, thus its oxidation is essentially irreversible. However, the oxidation of oxalate is a two-electron oxidation, whereas the reduction of the veratryl alcohol cation radical consumes only one electron. Therefore, the odd electron left in oxalate is available for other reductions. A number of electron acceptors can thus be reduced by lignin peroxidases provided with hydrogen peroxide, veratryl alcohol (which is now called a "mediator"), and oxalate (which has been termed the "donor"). The reductive dechlorination of carbon tetrachloride (a highly oxidized chemical) to the trichloromethyl radical was demonstrated with this system. The reductive dechlorination process was accomplished using a peroxidase, thus opening up a new field of investigation into the role of lignin peroxidases in the metabolism of chemicals requiring reductive dechlorination. http://ehpnet1.niehs.nih.gov/docs/1993/101-3/innovations.html Toxaphene is about 68% Cl as a result of a mixture of a possible 177 compounds from the chlorination of camphene a terpene isolated from pine trees. One form marketed as Lindane (gamma isomer). Toxaphene |
-HCH,
10-12% β-HCH, and other isomers (