Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.6.1.3 (ATPase)
 65,361 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Fat head minnows, 45-days old, were continuously exposed to DDT using continuous water flow and constant temperature conditions. Exposures were to 0.5 and 2.0 ppb of DDT in water, and combinations of the two concentrations with 50 ppm in food, and 50 ppm in food alone, using C1 4-DDT in food. Brain homogenates were analyzed for enzyme activity from fish treated for 56, 118, 225, and 266 days; and gill analysis was made at 225 and 226 days exposure. Enzyme reductions were greatest in oligomycin-sensitive (mitochondrial) Mg2+ ATPase, with pronounced effects (over 50% inhibition) at the 266th sampling day. In contrast, Na+-K+ ATPase and oligomycin-insensitive Mg2+ ATPase activities were activated by as much as 28% and 40%, respectively. Mitochondrial Mg2+ ATPase of fish brain has been inhibited to the greatest extent in previously reported in vitro studies. All three ATPase enzymes were reduced in gill tissue sampled at the 266th day, with mitochondrial Mg2+ ATPase showing the greatest decline.
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PMID:DDT: effect of continuous exposure on ATPase activity in fish, Pimephales promelas. 12 61

In rats treated with single, sublethal doses of p,p'-DDT oxidative phosphorylation efficiency, respiratory activity and "latent" ATPase activity in liver and brain mitochondria were determined. A time- and dose-dependent decrease in oxidative phosphorylation efficiency was found. Time-dependent suppression of respiratory activity in state 3 was noticed and a stimulation of mitochondrial ATPase activity 24 h after DDT treatment in liver and brain mitochondria was found. The correlation between time-dependent changes in the brain mitochondrial fraction and distribution of DDT in brain after a single, oral dose is discussed. It is suggested that changes in mitochondria were caused by DDT and its metabolites. It is concluded that the uncoupling of oxidative phosphorylation especially in brain mitochondria could be responsible for some DDT intoxication symptoms in mammals.
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PMID:The mode of action of p,p'=DDT on mammalian mitochondria. 13 71

Adult mallard ducks were fed a diet containing 50 ppm DDT for 6 months. Eggs laid during this period were collected and eggshell weight, thickness, and calcium were determined. Chronic ingestion of DDT resulted in production of eggshells that were significantly thinner and lighter than those of controls. Total calcium of thinned eggshells was also reduced; however, calcium per gram of eggshell was not altered, indicating that other eggshell constituents were not incorporated as well. Calcium adenosine triphosphatase activity in the microsomal fraction of eggshell gland epithelium was assayed in control and DDT-fed ducks. Enzyme activity in DDT-fed ducks was reduced to 65% of control values. Since Ca-ATPase has been shown to be associated with calcium transport, enzyme inhibition may be responsible for decreased eggshell weight and thickness. Electron microscopic evaluation of microsomal fractions showed elements of the plasma membrane, including cilia and microvilli, as well as rough and smooth endoplasmic reticulum. Inhibition of calcium transport at the plasma membrane of mucosal epithelium is proposed as a possible mechanism of DDT-induced eggshell thinning.
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PMID:Effects of DDT on eggshell quality and calcium adenosine triphosphatase. 14 96

Sarcoplasmic reticulum fragments capable of accumulating calcium were isolated from rat skeletal muscle by differential and sucrose gradient centrifugation. The ability of these fragments to accumulate calcium was impaired by adding 2,2-bis-(p-chlorophenyl)-1,1,1-trichloroethane (DDT) to the assay medium at concentrations of 0.06 to 6 muM. DDT (6 muM) caused a sharp lag in calcium uptake, with an 82% reduction in reaction rate 30 sec after calcium was added and a 62% reduction after one min. Basal ATPase activity of the microsomal fraction was inhibited by DDT but the calcium-stimulated increment of ATP hydrolysis was not. The findings show that DDT hinders calcium uptake by sarcoplasmic reticulum, but by some means other than inhibition of the calcium-stimulated ATPase. An apparent antagonism between DDT and ouabain or oligomycin was indicated. We propose that the presence of the lipid-soluble DDT molecule within the membrane of the sarcoplasmic reticulum interferes with the normal rapid uptake of calcium ions required for muscle relaxation, and that this interference may contribute to loss of muscle control in organisms poisoned by DDT.
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PMID:Calcium uptake by sarcoplasmic reticulum of rat muscle: inhibition by DDT. 15 30

The target enzymes, acetylcholinesterase (for phosphamidon and carbaryl) and Mg2+ ATPase (for DDT and fenvalerate) have been assayed during exposure and reclamation of these insecticides in M. monoceros. Toxicity of these insecticides are in the order: fenvalerate greater than DDT greater than carbaryl greater than phosphamidon. Reclamation studies show that fenvalerate is rapidly degradable while DDT is slowly degradable. It is suggested that pyrethroid, organophosphate and carbamate insecticides may be preferred over organochlorine compounds in farm operations.
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PMID:Inhibition and recovery of selected target enzyme activities in tissues of penaeid prawn, Metapenaeus monoceros (Fabricius), exposed to different insecticides. 183 18

Residues of organochlorine pesticides were monitored in the muscles of Bolti fish Tilapia zillii, the crab Lupa pelagicus and sediment samples collected from El Temsah lake around Ismailia using gas liquid chromatography. The beta isomer of hexachlorocyclohexane (beta.HCH) was the most dominant compound detected in all samples, followed by P, P-DDE and P, P-DDT. Results showed the crab to contain higher concentrations of organochlorine in comparison to concentrations detected in fish muscles. The In-vitro effect of the residues extracted from fish, and crab on the mitochondrial brain and liver ATPase of the New Zealand white rabbit Orcytolagus cuniculus was also studied. Residues of organochlorine pesticides have induced activation in the ATPase enzyme system of both brain and liver. The mixtures of organochlorine residues of both fish and crab were able to activate liver ATPase more than brain ATPase. The present study was conducted to extrapolate possible effects incurred on man if consumed such food.
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PMID:Residues of organochlorine pesticides in fish, crab and sediment from El Temsah Lake, Suez Canal, Egypt and their effect on mitochondrial ATPase of the New Zealand white rabbit. 183 60

The effect of exposure to chlorinated insecticides (DDT and toxaphene) on Na+,K+-ATPase, Mg2+-ATPase and Ca2+-ATPase activities of the plasma membrane of hepatocytes was determined. Acute treatment with DDT (200 mg per kg body weight) or toxaphene (110 mg per kg body weight) produced a significant decrease in Na+,K+-ATPase activity (80% and 85%, respectively) 24 h after treatment. DDT also produced a 30% decrease in Mg2+-ATPase and Ca2+-ATPase activity, but toxaphene treatment did not modify these enzymes. The effect of exposure to daily doses of DDT (30 mg per kg body weight) or toxaphene (16.5 mg per kg body weight) for a period of 3.5 months was also studied. Animals were sacrificed at 15-day intervals and results showed that Na+,K+-ATPase activity decreased 80% from the beginning of each treatment and the activity remained low throughout the treatment period. DDT, but not toxaphene, also led to a decrease in Mg2+-ATPase (20%) and Ca2+-ATPase (35%) activity. The low values observed from the beginning remained low throughout the treatment period. We believe that the general mechanism of ATPase inhibition by organochloride compounds could be the result of its interaction with membrane lipid components, although some differences could arise from differences in their spatial structure.
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PMID:Adenosine triphosphatase activities in plasma liver membranes of rats treated with DDT and toxaphene. 298 82

The effects of DDT on the energy-related functions of rat-liver mitochondria were examined. ADP-stimulated respiration was much more sensitive to inhibition by DDT than was uncoupler-stimulated respiration when succinate or ascorbate/TMPD was used as the substrate. Ca2+ uptake driven by ATP hydrolysis was inhibited by DDT. These results indicate that DDT inhibits ATPase itself. In addition, DDT blocked succinate dehydrogenase and the cytochrome b-c span of the electron transport chain, which also secondarily reduced ATP synthesis. The uncoupling action due to DDT was only seen at high concentrations with ascorbate/TMPD as the substrate. However, this action was masked because of the increased inhibition of the electron transport chain when the substrate was changed to succinate.
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PMID:Effects of 1,1,1-trichloro-2,2-bis-(p-chlorophenyl)ethane (DDT) on ATPase-linked functions in isolated rat-liver mitochondria. 315 37

The insecticide DDT selectively inhibits the action of a Na(+), K(+), Mg(2+)-adenosine triphosphatase found in the nerve ending fraction of the rat brain. As judged by the concentrations of inhibitors that give 50 percent of enzyme inhibition, DDT was approximately 1000 times more toxic than its non-insecticidal analog, 1,1-dichloro-2,2-bis(p-chlorophenyl)ethylene. The degrees of inhibition of this enzyme system by various toxic and nontoxic DDT analogs were closely related to a general toxicity in vivo of these compounds. Moreover, the extents of inhibition of this enzyme system by DDT were much higher at low temperatures, an indication of a causal relation between poisoning in vivo by DDT and the inhibition in vitro of the Na(+), K(+), Mg(2+)-adenosine triphosphatase system.
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PMID:Adenosine triphosphatase. Sensitive to DDT in synapses of rat brain. 424 26

The drinking of seawater and absorption of water along with sodium across the intestinal epithelium are well-known osmoregulatory events in marine teleosts. The insecticide DDT impairs fluid absorption in intestinal sacs from eels adapted to seawater. Furthermore, this functional impairment has an enzymatic basis; DDT also inhibits the (Na(+) and K(+)) activated, Mg(2+)-dependent adenosine triphosphatase in homogenates of the intestinal mucosa. Thus, the extreme sensitivity of teleosts to organochlorine pollutants may involve the disruption of osmoregulatory transport mechanisms.
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PMID:DDT: disrupted osmoregulatory events in the intestine of the eel Anguilla rostrata adapted to seawater. 425 81


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