title: Regional distribution of the histamine metabolite, tele-methylimidazoleacetic acid, in rat brain: effects of pargyline and probenecid.
abstract: tele-Methylimidazoleacetic acid (t-MIAA), a major brain histamine metabolite, was measured in nine rat brain regions by a gas chromatography-mass spectrometric method that also measures the precursor amine, tele-methylhistamine (t-MH). The t-MIAA concentration of cerebellum, medulla-pons, midbrain, caudate nucleus, hypothalamus, frontal cortex, hippocampus, and thalamus varied 15-fold, hypothalamus showing the highest level (2.21 nmol/g) and cerebellum the lowest (0.15 nmol/g). The concentrations of t-MIAA and t-MH were significantly correlated in all regions except midbrain, which had relatively more t-MIAA. Probenecid did not alter whole-brain t-MIAA levels. Treatment with pargyline, an inhibitor of monoamine oxidase, lowered the t-MIAA levels in all regions.
mesh_terms: D000818:Animals; D001921:Brain / Q000187:drug effects / Q000378:metabolism*; D006632:Histamine / Q000378:metabolism*; D007093:Imidazoles / Q000378:metabolism*; D008297:Male; D010293:Pargyline / Q000494:pharmacology*; D011339:Probenecid / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains; D014018:Tissue Distribution
chemical_list: D007093:Imidazoles; C002667:methylimidazoleacetic acid; D006632:Histamine; D010293:Pargyline; D011339:Probenecid