title: Effects of short-term toluene exposure on ligand binding to muscarinic acetylcholine receptors in the rat frontal cortex and hippocampus.
abstract: Changes in the binding affinity of the muscarinic acetylcholine receptor agonist carbamylcholine were determined in membranes isolated from the brains of rats exposed to toluene at concentrations of 500-2,000 ppm for 6 h. Membrane fractions of the frontal cortex and hippocampus were prepared and agonist-binding affinities were determined by measuring the displacement of [3H]N-methyl scopolamine-binding activity by carbamylcholine. In the frontal cortex, the affinity of high-affinity carbamylcholine binding was reduced following exposure to toluene at a concentration of 1000 ppm or higher. However, in the hippocampus, the affinity of high-affinity binding of carbamylcholine was increased following exposure to toluene. These observations suggest that toluene exposure affects binding affinity of carbamylcholine, and the effect differs by brain region.
authors.affiliation: Division of Health Effects Research, National Institute of Industrial Health, Kawasaki, Kanagawa 214-8585, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Tsuga
authors.forename: T
authors.initials: T
authors.lastname: Honma
mesh_terms: D000818:Animals; D001667:Binding, Competitive / Q000187:drug effects; D002217:Carbachol / Q000378:metabolism / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D005625:Frontal Lobe / Q000187:drug effects / Q000378:metabolism*; D006624:Hippocampus / Q000187:drug effects / Q000378:metabolism*; D019570:Inhalation Exposure; D008297:Male; D008566:Membranes / Q000187:drug effects / Q000378:metabolism; D019832:N-Methylscopolamine / Q000378:metabolism; D011869:Radioligand Assay; D051381:Rats; D011916:Rats, Inbred F344; D011976:Receptors, Muscarinic / Q000378:metabolism*; D013997:Time Factors; D014050:Toluene / Q000633:toxicity*; D014316:Tritium
chemical_list: D011976:Receptors, Muscarinic; D014316:Tritium; D014050:Toluene; D002217:Carbachol; D019832:N-Methylscopolamine