Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0040822 (tremor)
 18,428 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Pretreatment of rats with hydantoin (75 mg/kg, PO, an anticonvulsant), trihexyphenidyl (10 mg/kg, SC, a muscarinic cholinergic antagonist), or piperonyl butoxide (500 mg/kg, PO, a metabolic inhibitor) had no effect on the whole blood or brain tissue levels of orally administered DDT (75 mg/kg) or its metabolites DDD and DDE. Hydantoin and piperonyl butoxide decreased DDT-induced tremor and hyperthermia due to DDT when measured 12 h after DDT exposure, while trihexyphenidyl augmented some components of DDT-induced tremor. Additional experiments found that pretreatment with piperonyl butoxide increased tremor due to permethrin exposure (120 mg/kg, PO), while having no effect on tremor due to chlordecone administration (60 mg/kg, IP). Pretreatment with ellipticine (30 mg/kg, IP, a metabolic inhibitor) also decreased tremor 12 h after DDT exposure. The effects of piperonyl butoxide and ellipticine on DDT-induced tremor are postulated to occur through direct actions of these compounds on nerve or muscle tissue. Hydantoin-induced attenuation of DDT-induced neurotoxicity may be due to the ability of hydantoin to block repetitive firing of nerves by binding to the inactivation gates of sodium.
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PMID:Pharmacological modification of DDT-induced tremor and hyperthermia in rats: distributional factors. 308 50

The DDT syndrome in rats consists of tremor, myoclonus, running seizures, hyperthermia, episodic boxing, and excessive grooming. DDT did not change whole-brain glycine levels when the rats had stimulus-sensitive myoclonus, spontaneous myoclonus, or seizures. However, regional analysis showed a decrease in glycine levels in the pons and medulla initially, but they rose again despite worsening of the myoclonus. Glycine given intraventricularly and the glycine prodrug, milacemide, given intraperitoneally suppressed DDT-induced myoclonus. A dose of milacemide that prevented DDT-induced myoclonus caused a significant increase in glycine levels in cortex, septum accumbens, cerebellum, striatum, hippocampus diencephalon, midbrain, pons, and medulla. The increase was most marked in the forebrain structures. There was no change in serine levels in these areas. These data suggest that the glycinergic system may be playing an important role in the manifestation of DDT-induced myoclonus.
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PMID:Glycine involvement in DDT-induced myoclonus. 317 67

p,p'-DDT (1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane; 75 mg/kg) or corn oil was administered po to male Fischer 344N rats. Tremor was quantified 8 hr later by spectral analysis of whole body movements. The effect of sc injection of pharmacological challenges on the spectral profile of body movements was determined. The alpha antagonist phenoxybenzamine decreased the intensity of movements over most of the power spectra in animals exposed to DDT, but decreased spectral power only at lower frequencies in control subjects. The alpha-1 antagonist prazosin had similar effects in animals given DDT. The alpha-2 antagonist yohimbine and the beta antagonist propranolol produced lethality and increased the intensity of movements in animals administered DDT, without significantly affecting control animals. The alpha-2 agonist clonidine decreased the spectral profile over a wide range of frequencies in animals exposed to DDT, while depressing the spectral power of control animals only at higher frequencies. The dopamine antagonist haloperidol increased the intensity of movements in DDT-treated animals, without altering the spectral profile of controls. The dopamine agonist apomorphine induced stereotypy in control animals, but failed to significantly alter the power spectra in subjects given DDT. These data suggest a facilitatory and inhibitory role, respectively, for alpha-1 and alpha-2 receptors in the modulation of DDT-induced tremor. Dopamine and beta receptors may be involved in the tonic inhibition of tremor produced by DDT.
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PMID:Modulation of p,p'-DDT-induced tremor by catecholaminergic agents. 367 20

Rats given a tremorigenic dose of DDT (75 mg/kg, PO) were treated with pharmacological agents either 30 min prior to DDT or 1-2 h prior to testing at the time of peak effect (12 h postdosing). The administration of mephenesin (a centrally acting muscle relaxant) or Dilantin (an anticonvulsant) prior to DDT significantly attenuated tremor. Pretreatment with pizotifen (a serotonergic receptor antagonist) had no significant effect on tremor. Administration of the same agents 1-2 h prior to measurement had minimal effects. Trihexyphenidyl (a muscarinic cholinergic receptor antagonist) exacerbated the tremor produced by DDT. These data suggest that cholinergic neurotransmitter systems may be involved in DDT-induced tremor. That DDT-induced tremor was significantly attenuated by mephenesin and Dilantin is in accord with the conclusion that DDT-induced tremor is a manifestation of repetitive discharge due to interference with ionic conductance.
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PMID:DDT-induced tremor in rats: effects of pharmacological agents. 392 13

Rats were given various doses of chlordecone, 1,1,1-trichloro-2,2-bis(p-chloro-phenyl)ethane (DDT) and lindane and tested for neurobehavioral toxicity up to 24 hr postdosing. The organochlorines either had no effect or increased responsiveness to an acoustic stimulus at subconvulsant doses. Only chlordecone and p,p'-DDT produced tremor. For purposes of comparison, the neurobehavioral effects of permethrin were also studied; this pyrethroid insecticide produced tremor and hyperresponsiveness similar to that of p,p'-DDT. Pretreatment with phenytoin significantly reduced the tremor and hyperresponsiveness produced by p,p'-DDT and permethrin. On the other hand, pretreatment with phenytoin increased the responsiveness of animals dosed with chlordecone or lindane, suggesting that these agents differ in their mechanism of action from p,p'-DDT and permethrin. The results of our experiments also indicate that care should be taken in the choice of agents, particularly anticonvulsants, to be used to treat symptoms of insecticide toxicity.
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PMID:Effects of 5,5-diphenylhydantoin (phenytoin) on neurobehavioral toxicity of organochlorine insecticides and permethrin. 399 19

Impaired glycinergic inhibition causes human hyperekplexia, and may be involved in the pathogenesis of movement disorders associated with uremia, spinal cord lesions, DDT poisoning, and tetanus. Three autosomal recessive mutant mouse strains with single-gene mutations affecting either the alpha 1 (spasmodic and oscillator) or beta (spastic) subunits of the glycine receptor were studied. Serial videotaped examinations assessed the severity of hyperkinetic features. Homozygote oscillator mice appeared normal until postnatal day (P) 11-14, when decreased exploratory movements, spastic gait, stimulus-induced myoclonic bouts, rigidity, and tremor were noticeable. All symptoms gradually worsened until death by P21-P23. In contrast, spastic and spasmodic mice were most severely affected by the 3rd-5th week of life and had a lessening of symptom severity in adulthood. Within each mutant strain, there was marked interanimal variation of severity of the other motor abnormalities, possibly because of stochastic variability in developmental processes. These mutants represent good animal models for elucidation of molecular and cellular issues regarding the glycine receptor and for the study of pathogenetic mechanisms of movement disorders.
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PMID:Phenotypic heterogeneity and disease course in three murine strains with mutations in genes encoding for alpha 1 and beta glycine receptor subunits. 908 81

A procedure of clean-up with H2SO4 after extraction with a shaking machine using n-hexane, and fast determination of some organochlorine residues in eggs by GC-ECD with PCB2 and PCB209 as internal standards was established. The test results showed that with this method satisfactory recoveries(84.31%-116.77%), relative standard deviation (6%-18%) and detection limits (0.07 ng/g-0.35 ng/g) could be obtained. In comparing with the Soxhlet method, this method is simpler in pre-treatment, lower in cost and less in sample amount. It can determine organochlorine pesticides and some PCBs in the same extract, simultaneously with enough accuracy, sensitivity and permissible RSD. It is a suitable procedure for determining micro-amounts of organochlorine pollutants in foods. The results showed that p, p'-DDE was detected in maximum; p, p'-DDT next; and PCBs very little, that were usually less than 10 ng/g in the eggs from some Chinese markets. It was found that most of PCBs in eggs were the congeners with 3-5 chlorine atoms.
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PMID:[Determination of organochlorine pesticides and polychlorinated biphenyl congeners residues in eggs by gas chromatography with electron capture detection (GC-ECD)]. 1254 78

Three different calcareous soil samples from Lebanon were analyzed for total DDT pesticide residue using GC and ELISA methods. Two experiments were conducted on three different calcareous soil samples. In each experiment, triplicates of 5 gm soil samples were each fortified with standard solutions of DDE to reach concentrations of 0, 5, 25, 50, 100 and 200 ng g(-1) and allowed to equilibrate at room temperature for 6 hours. Each sample was then extracted with 25 mL of 90% methanol by shaking in glass bottles on a mechanical shaker for 16 hours. The bottles were allowed to stand for 30 minutes and aliquots were taken from the clear supernatant for analyses without further cleanup. The total DDT in the extract was measured in triplicate by GC and ELISA. The results indicated that the two methods were highly correlated (R = 0.955-0.994). Differences in soil properties did not affect the accuracy of the detection limits of ELISA. Immunoassay technique can be used for rapid and accurate measurement of total DDT residues in mineral calcareous soils in Lebanon.
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PMID:Comparison of gas chromatography and immunoassay methods for analysis of total DDT in calcareous soils. 1261 50

Ecotoxicological hazards of 1,1,1-trichloro-2,2-bis(4-chlorophenyl)ethane (p,p'-DDT) were investigated by a one-generation reproduction study using Japanese quail (Coturnix coturnix japonica) under an Organization for Economic Co-operation and Development (OECD) draft new test guideline 206 following acute and subchronic toxicity studies. In the subchronic feeding toxicity study, tremors, convulsions, and deaths were observed with a clear sex difference, males being more susceptible than females. The estimated total number of sperm tended to decrease in a dose-dependent manner at the end of 6-week treatment. In the one-generation reproduction study conducted at dose levels of 0, 6, 30, and 150 ppm, the estimated total number of sperm tended to decrease in a dose-dependent manner with a significant difference at 150 ppm. Tremors were observed in the majority of hatchlings in the 150 ppm group and at lower incidences in the 30 ppm group. Significantly high mortality rate in chicks persisted from treatment week 3-6 in the 150 ppm group and at treatment weeks 4 and 5 in the 30 ppm group. Despite of these severe adverse effects of p,p'-DDT on hatchlings and chicks, fertilization, egg laying, eggshell thickness or embryonic development was hardly impaired by p,p'-DDT or its metabolites. From these results, it appears that the OECD draft new avian one-generation reproduction test guideline is effective for ecological hazard assessment of chemicals.
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PMID:Reassessment of ecotoxicities of 1,1,1-trichloro-2,2-bis(4-chlorophenyl)ethane in Japanese quail under the OECD draft new avian one-generation reproduction test guideline. 1574 94

Essential tremor (ET) is a common neurological disorder. Its etiology and pathogenesis are not well understood and several environmental factors (i.e., toxicants) have been studied. Organochlorine pesticides (OCPs) are potent tremor-producing chemicals. These pervasive environmental contaminants have been linked with other tremor disorders (e.g., Parkinson's disease) but they have not been assessed in ET cases. Our objective was to test the hypothesis that ET is associated with OCP exposure. Serum OCP concentrations and lifetime occupational histories were assessed in ET cases and control subjects. Six serum OCP concentrations (p,p'-DDE, p,p'-DDT, beta-hexachlorocyclo-hexane, oxychlordane, trans-nonachlor, and dieldrin) were assessed. Data from a lifetime occupational history were reviewed by a blinded industrial hygienist. The six serum OCP concentrations were similar in 136 ET cases and 144 control subjects. There was no association in ET cases between the six serum OCP concentrations and total tremor score. Three (2.2%) ET cases versus 9 (6.3%) controls had past occupational exposure to OCPs (OR=0.34, 95% CI=0.09-1.28, p=0.10). Although OCPs have been associated with other tremor disorders, we were not able to find an association between the six most tremorogenic OCPs and ET. Our data suggest that these tremor-producing chemicals are not of major etiological importance in our patients with ET.
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PMID:Organochlorine pesticide exposure in essential tremor: a case-control study using biological and occupational exposure assessments. 1662 Sep 96


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