Effect of alpha-fluoromethylhistidine on the histamine content of the brain of W/Wv mice devoid of mast cells: turnover of brain histamine.
In the brains of W/Wv mutant mice that have no mast cells, the histidine decarboxylase (HDC) level is as high as in the brain of congenic normal mice (+/+), but the histamine content is 53% of that of +/+ mice. The effects of alpha-fluoromethylhistidine (alpha-FMH) on the HDC activity and histamine content of the brain of W/Wv and +/+ mice were examined. In both strains, 30 min after i.p. injection of alpha-FMH the HDC activity of the brain had decreased to 10% of that in untreated mice. The histamine content decreased more gradually, and after 6 h about half of the control level remained in +/+ mice, whereas histamine had disappeared almost completely in W/Wv mice. It is concluded that the portion of the histamine content that was depleted by HDC inhibitor in a short time is derived from non-mast cells, probably neural cells. The half-life of histamine in the brain of W/Wv mice was estimated from the time-dependent decrease in the histamine content of the brain after administration of alpha-FMH: 48 min in the forebrain, 103 min in the midbrain, and 66 min in the hindbrain.
D000818:Animals; D001921:Brain / Q000187:drug effects / Q000378:metabolism*; D006632:Histamine / Q000378:metabolism*; D006639:Histidine / Q000031:analogs & derivatives*; D006640:Histidine Decarboxylase / Q000378:metabolism; D007700:Kinetics; D008407:Mast Cells / Q000502:physiology*; D008762:Methylhistidines / Q000494:pharmacology*; D051379:Mice; D008818:Mice, Neurologic Mutants; D014018:Tissue Distribution
D008762:Methylhistidines; D006639:Histidine; C028309:alpha-fluoromethylhistidine; D006632:Histamine; D006640:Histidine Decarboxylase