Effects of cyclodiene compounds on calcium pump activity in rat brain and heart

Mehrotra, B.D.; Moorthy, K.S.; Reddy, S. Ravichandra; Desaiah, Durisala

doi:10.1016/0300-483x(89)90075-9

Cited by 18 publications

(8 citation statements)

References 23 publications

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“…Another study with mipafox showed inhibition of Ca+ +-ATPase until the 14th day after treatment. Decreased Ca+ + pump activity would adversely affect the intracellular Ca+ + homeostasis (13,21); there are several reports indicating Ca+ +-dependent events in neuronal cells during OPIDN (9)(10)(11)(12). Increased calciumactivated neutral protease activity in brain and sciatic nerve, increased total sciatic nerve calcium level, and protection by calcium channel blocker have also been reported during OPIDN (31).…”

Section: Discussionmentioning

confidence: 99%

Section: Fu-14cl Glycine Uptake By Cerebral Cortex Slicesmentioning

confidence: 99%

“…The supernatant was centrifuged at 9000 X g for 20 minutes, and the pellet was dispersed in 0.32 M sucrose and recentrifuged. The resultant pellet was suspended in 0.25 M sucrose and kept aside for enzyme assays (21). Na+, K+-ATPase was assayed as the difference in rate of release of inorganic phosphate from ATP in the presence and absence of 1 mM ouabain.…”

Section: Fu-14cl Glycine Uptake By Cerebral Cortex Slicesmentioning

confidence: 99%

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Altered glycine transport by cerebral tissue and decreased Na⁺ and Ca⁺⁺ pump activities during organophosphorus‐ester–induced delayed neurotoxicity development period

Sharma

Bhattacharya

1995

J. Biochem. Toxicol.

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Uptake of [U-14C] glycine during the organophosphorus-ester-induced delayed neurotoxicity (OPIDN) development period was studied. Diisopropyl fluorophosphate (DFP), a delayed neurotoxic organophosphorus ester was administered to adult rats and hens. Results showed a decreased accumulation of glycine in hen cerebral cortex slices during the delayed neurotoxicity development period. An altered sensitivity toward transport inhibitors 2,4-dinitrophenol and ouabain was observed in DFP-treated hens. An altered neuronal membrane function during the OPIDN development period is reported in the present work. Brain Na+, K(+)-ATPase and Ca(++)-ATPase activities decreased during the neurotoxicity development period. The decrease in Ca(++)-ATPase activity persisted in hens until the complete development of neurotoxic symptoms. Decreased Ca++ pump activity is correlated with altered membrane function during OPIDN.

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Section: Discussionmentioning

confidence: 99%

Section: Fu-14cl Glycine Uptake By Cerebral Cortex Slicesmentioning

confidence: 99%

Section: Fu-14cl Glycine Uptake By Cerebral Cortex Slicesmentioning

confidence: 99%

See 1 more Smart Citation

Altered glycine transport by cerebral tissue and decreased Na⁺ and Ca⁺⁺ pump activities during organophosphorus‐ester–induced delayed neurotoxicity development period

Sharma

Bhattacharya

1995

J. Biochem. Toxicol.

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“…Triorganotins cause brain edema [9], myelin degeneration [25,3,2] and reduction of neurotransmitter levels [5,30]. In an attempt to understand the molecular mechanism^) involved in the neurotoxicity of these compounds, we investigated their effects on calmodulin-dependent enzymes involved in Ca 2+ -transport across the synaptic membranes and cAMP metabolism both in vitro and in vivo [7,8,20,19,15,31,29]. Plictran and chlordecone are very potent inhibitors of synaptic membrane Ca 2+ -ATPase indicating their greater neurotoxic action when compared to other insecticides studied [7,18,23].…”

Section: Introductionmentioning

confidence: 99%

Effect of Organochlorine and Organotin Compounds on Active Conformation of Calmodulin

Vig

Yallapragada

Trottman

et al. 1991

Journal of Environmental Science and Health . Part A: Environme

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The interaction of organotin and organochlorine compounds with calmodulin was studied in order to elucidate whether these compounds interact with calmodulin thereby affecting its active conformation. The 522 VIG ET AL.conformational changes in calmodulin were studied by using N-phenyl-1-naphthylamine (NPN) and dansyl-calmodulin as fluorescent probes. Chlordecone, an organochlorine compound, suppressed the increase in fluorescence of NPN by complex formation with calmodulin in the presence of Ca 2+ and the effect was concentration dependent with IC 50 of 9.25 µM. However, no effect was observed in the presence of 1 mM EGTA. Other organochlorine compounds such as aldrin, dieldrin, endrin and isodrin even at high concentrations (80 µM) did not affect the Ca 2+ -dependent change in calmodulin conformation. Chlordecone (20 µM) also inhibited the Ca 2+ -dependent increase in dansyl-calmodulin fluorescence. This chlordecone-induced, conformationally changed calmodulin (involving the high affinity Ca 2+ -binding sites) was unable to form a Ca 2+ -dependent complex with phosphodiesterase. Unlike, chlordecone, organotin compounds such as tributyltin (TBT) and triethyltin (TET) increased the NPN fluorescence with ED 50 of 5.2 and 175 µM respectively. This effect was Ca 2+ -dependent. Trimethyltin did not affect NPN fluorescence both in the presence and absence of Ca 2+ . TBT also increased Ca 2+ -dependent dansyl-calmodulin fluorescence in a concentration dependent manner. These data suggest that not all compounds interact directly with calmodulin. Chlordecone and TBT alter the active conformation of calmodulin by interacting at different sites on calmodulin.

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“…In a study of the effects of cyclodiene compounds on calcium pump activity in rat brain and heart (Mehrotra et al, 1989), rats (not further specified) received dieldrin at 1, 5 or 10 mg/kg bw by oral intubation for 3 days and were killed 24 hours after the last treatment. Distinct behavioural changes, such as tremors and convulsions, were observed in the animals receiving the highest dose, but without mortality.…”

Section: Neurotoxicitymentioning

confidence: 99%

Opinion of the Scientific Panel on Plant protection products and their Resi-dues on a request from the Commission on the risks associated with an in-crease of the MRL for dieldrin on courgettes

2007

EFSA Journal

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SUMMARYFollowing a request from the European Commission, the Panel on Plant Protection Products and their Residues (PPR Panel) was asked to deliver a scientific opinion on the risks associated with an increase of the MRL for dieldrin on courgettes.Dieldrin was developed in the 1940s and was widely used as an insecticide up to the early 1970s. However, its use was stopped when it became clear that it has very unfavourable environmental and toxicological characteristics. Today, dieldrin is therefore banned in most countries of the world. Moreover, it is on the list of the Stockholm Convention to protect human health and the environment from persistent organic pollutants.Dieldrin is very persistent in the environment and has a strong potential to accumulate in the food chain. Due to the very slow environmental degradation of the substance, dieldrin is still a widespread soil contaminant in Europe and other places. When growing courgettes on such soils, residues can be taken up by the plants and transported to the fruits. Monitoring data from The Netherlands show that courgettes grown in greenhouses from the western part of the country do not always comply with the existing MRL of 0.02 mg/kg. The Netherlands has therefore requested an increase of this MRL-value to 0.05 mg/kg and the European Commission has asked EFSA to evaluate the toxicological implications of the proposed new MRL-value.The main reasons for prohibiting the active substance were its environmental persistence and its tendency to accumulate in animal tissues. It is therefore appropriate to ask whether exposure as a result of eating courgettes with an increased MRL, together with other known sources of exposure (e.g. through animal products), represents a potential risk for European consumers in the long as well as in the short term.The residue definition for dieldrin under current EU residue guidelines specifies dieldrin "singly or combined with aldrin, expressed as dieldrin". This definition reflects the close chemical and toxicological relationship between these two cyclodiene insecticides. There are two isomers of dieldrin, the exo-and the endo-form. Dieldrin itself is the exo-isomer. The PPR Panel 2 briefly reviewed the characteristics of the different isomeric forms of dieldrin and concluded that focus should be on the exo-form of the substance, i.e. dieldrin itself. The Panel agreed not to include photodieldrin -an environmental product of dieldrin -in further consideration because this substance is not included in the residue definition. Furthermore photodieldrin has not been studied in such detail and the literature and data on the occurrence and fate of its residue are scarce.The Joint FAO/WHO Meeting on Pesticide Residues (JMPR) established an acceptable daily intake (ADI) for dieldrin in 1967, confirmed this in 1977 and converted (but not re-evaluated) it to a PTDI (Provisional Tolerable Daily Intake) in 1994. JMPR has not derived an acute reference dose (ARfD) for dieldrin. The propensity of dieldrin to accumulate in biological organisms...

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Effects of cyclodiene compounds on calcium pump activity in rat brain and heart

Cited by 18 publications

References 23 publications

Altered glycine transport by cerebral tissue and decreased Na⁺ and Ca⁺⁺ pump activities during organophosphorus‐ester–induced delayed neurotoxicity development period

Altered glycine transport by cerebral tissue and decreased Na⁺ and Ca⁺⁺ pump activities during organophosphorus‐ester–induced delayed neurotoxicity development period

Effect of Organochlorine and Organotin Compounds on Active Conformation of Calmodulin

Opinion of the Scientific Panel on Plant protection products and their Resi-dues on a request from the Commission on the risks associated with an in-crease of the MRL for dieldrin on courgettes

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Effects of cyclodiene compounds on calcium pump activity in rat brain and heart

Cited by 18 publications

References 23 publications

Altered glycine transport by cerebral tissue and decreased Na+ and Ca++ pump activities during organophosphorus‐ester–induced delayed neurotoxicity development period

Altered glycine transport by cerebral tissue and decreased Na+ and Ca++ pump activities during organophosphorus‐ester–induced delayed neurotoxicity development period

Effect of Organochlorine and Organotin Compounds on Active Conformation of Calmodulin

Opinion of the Scientific Panel on Plant protection products and their Resi-dues on a request from the Commission on the risks associated with an in-crease of the MRL for dieldrin on courgettes

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Altered glycine transport by cerebral tissue and decreased Na⁺ and Ca⁺⁺ pump activities during organophosphorus‐ester–induced delayed neurotoxicity development period

Altered glycine transport by cerebral tissue and decreased Na⁺ and Ca⁺⁺ pump activities during organophosphorus‐ester–induced delayed neurotoxicity development period