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Author (up) Berzins, D.W.; Bundy, K.J. file  url
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  Title Bioaccumulation of lead in Xenopus laevis tadpoles from water and sediment Type Journal Article
  Year 2002 Publication Environment International Abbreviated Journal Environ Int  
  Volume 28 Issue 1-2 Pages 69-77  
  Keywords Animals; Body Weight/drug effects; Environmental Pollutants/*pharmacokinetics/toxicity; Fresh Water/chemistry; Geologic Sediments/chemistry; Larva/*chemistry/growth & development; Lead/*pharmacokinetics/toxicity; Louisiana; *Xenopus  
  Abstract The overall objective of this research was to monitor the uptake kinetics of lead in an amphibian model and correlate metal content with embryo development. Based upon the concentration of lead found in the water and sediment of a Louisiana swamp adjacent to a Superfund site, a controlled laboratory experiment exploring lead uptake from water and sediment by Xenopus laevis tadpoles was conducted. For 5 weeks, tadpoles were exposed to water and a simulated sediment, kaolin, spiked with 1, 5, or 10 times the concentration of lead found in field water and sediment samples. Additionally, organisms were exposed to the 5 x condition for 3 and 6 weeks. The experimental controls consisted of unexposed tadpoles and ones exposed to lead originating from water or sediment exclusively. At the end of the exposure periods, developmental data, i.e., body weight and developmental stage, were recorded, and the tadpoles were analyzed for whole body lead concentration. Lead extraction was accomplished by dry ashing, and its amount was quantified polarographically. Results showed that lead inhibited the normal development of these amphibians, in a manner that generally was more severe as exposure level increased. The hindrance of tadpole development also coincided with an increase in whole body lead concentration at higher exposures. Temporally, at the 5 x exposure concentration, the mean lead level increased with time, but this difference was not statistically significant (P<.05). Additionally, control animals exposed to lead (either in water or in sediment) showed no statistical difference with regard to weight and lead uptake, indicating that lead originating from both water and sediment is incorporated into the tadpole. The controlled laboratory experimental protocol used here is thus capable of investigating the uptake of a single metal (Pb in this case) and determining its effect on the development of tadpoles while differentiating the significance of multiple sources of exposure.  
  Call Number Serial 1183  
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Author (up) Holloway, W.R.J.; Thor, D.H. file  url
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  Title Acute and chronic caffeine exposure effects on play fighting in the juvenile rat Type Journal Article
  Year 1984 Publication Neurobehavioral Toxicology and Teratology Abbreviated Journal Neurobehav Toxicol Teratol  
  Volume 6 Issue 1 Pages 85-91  
  Keywords Aggression/*drug effects; Animals; Behavior, Animal/drug effects; Body Weight/drug effects; Caffeine/*toxicity; Drinking/drug effects; Humans; Male; Motor Activity/drug effects; Rats; Social Isolation  
  Abstract Effects of acute and chronic exposure to caffeine on the behavior of juvenile rats were assessed in three experiments. In Experiment 1, two indices of play fighting--pin frequency and duration--were decreased and locomotor activity was increased in dose dependent fashions by caffeine. Social investigation of another juvenile was not affected by the drug. In Experiment 2, juvenile rats were isolated and given caffeine in their drinking fluid for 10-11 days. Play fighting was increased by all except the highest caffeine dose. In Experiment 3, juveniles were housed in groups of four and received either tap water or caffeine in their drinking fluid. Pin frequency of caffeine treated subjects was lower than controls on days 2-4, and higher than controls on days 9-11 after caffeine treatment was initiated. Evidently, caffeine has inhibitory and facilitatory effects on juvenile play fighting behavior, contingent on duration of exposure to the drug.  
  Call Number Serial 1575  
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Author (up) Holloway, W.R.J.; Thor, D.H. file  url
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  Title Caffeine and social investigation in the adult male rat Type Journal Article
  Year 1983 Publication Neurobehavioral Toxicology and Teratology Abbreviated Journal Neurobehav Toxicol Teratol  
  Volume 5 Issue 1 Pages 119-125  
  Keywords Analysis of Variance; Animals; Body Weight/drug effects; Caffeine/*toxicity; Dose-Response Relationship, Drug; Drinking/drug effects; Male; Motor Activity/drug effects; Rats; *Social Behavior  
  Abstract In three experiments with adult rats, caffeine (0, 10, 20, 40 mg/kg) was found to increase the social investigation of a novel juvenile conspecific. Activity was elevated only after caffeine injections, whereas the duration of social investigation was raised after both the injection of caffeine and the administration of caffeine via the drinking water, suggesting the mechanisms of action of caffeine on these two behaviors may be independent. Duration and frequency of investigation were each increased following caffeine exposure, but the amount of investigation/episode was not influenced by this substance. Finally, the acute response to caffeine was not altered by prior exposure to the methylxanthine in the subject's drinking water.  
  Call Number Serial 1188  
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