Effects of chronic lead (Pb) exposure on neurobehavioral function and dopaminergic neurotransmitter receptors in rats.
Sprague-Dawley rats were maternally and permanently exposed to Pb (1000 ppm in their drinking water as lead acetate). Behavioral functions were examined starting at post-natal day (PN) 84. Lead exposure did not change spatial learning in the radial arm maze, but induced higher locomotor activity as observed in the open-field and in the radial arm maze. Lead treatment did not impact motor coordination. Autoradiographic analysis of brain sections indicated that Pb-exposure did produce a decrease in [125I]sulpride (D2 receptor antagonist) binding in the cerebral cortex, but not in the striatum and thalamus nucleus. No change was found in [125I]SCH-23982 (D1 receptor antagonist) binding. Since the cortical dopaminergic system is critical for cognitive processes and motor behavior, it is possible that Pb-related change in D2 receptors may mediate to it induced hyperlocomotor activity.
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Department of Pharmacology and Toxicology, University of Mississippi Medical Center, Jackson 39216, USA.
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D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects; D001552:Benzazepines / Q000031:analogs & derivatives / Q000378:metabolism / Q000494:pharmacology; D001667:Binding, Competitive; D001921:Brain / Q000187:drug effects / Q000378:metabolism; D002540:Cerebral Cortex / Q000187:drug effects / Q000378:metabolism; D018492:Dopamine Antagonists / Q000378:metabolism / Q000494:pharmacology; D065127:Dopamine D2 Receptor Antagonists; D005260:Female; D006624:Hippocampus / Q000187:drug effects / Q000378:metabolism; D007457:Iodine Radioisotopes; D007854:Lead / Q000008:administration & dosage / Q000009:adverse effects*; D018811:Maternal Exposure / Q000009:adverse effects*; D018782:Maze Learning / Q000187:drug effects; D008570:Memory, Short-Term / Q000187:drug effects; D017072:Neostriatum / Q000187:drug effects / Q000378:metabolism; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects; D011597:Psychomotor Performance / Q000187:drug effects*; D051381:Rats; D017207:Rats, Sprague-Dawley; D011954:Receptors, Dopamine / Q000187:drug effects* / Q000378:metabolism; D017447:Receptors, Dopamine D1 / Q000037:antagonists & inhibitors; D013469:Sulpiride / Q000378:metabolism / Q000494:pharmacology; D013787:Thalamic Nuclei / Q000187:drug effects / Q000378:metabolism
C049558:8-iodo-2,3,4,5-tetrahydro-3-methyl-5-phenyl-1H-3-benzazepine-7-ol; D001552:Benzazepines; D018492:Dopamine Antagonists; D065127:Dopamine D2 Receptor Antagonists; D007457:Iodine Radioisotopes; D011954:Receptors, Dopamine; D017447:Receptors, Dopamine D1; D007854:Lead; D013469:Sulpiride