Histamine in the rat brain: effect of treatment with histidine, histamine H1-, and H2-receptor antagonists and tricyclic antidepressant drugs.
L-Histidine (L-HIS), but not D-histidine (each 0.5 g/kg, ip), increased histamine (HI) level in both whole brain as well as in particular brain structures of the rat by approximately 50-60% after 2 hr. Four hours after L-HIS the amine content was still substantially elevated. H1-receptor antagonist, mepyramine (5 and 30 mg/kg ip) and H2-receptor antagonist, cimetidine (25-250 microgram ivt), being ineffective in changing HI level i the brain when given alone, exhibited a slight tendency, respectively, to increase (by 30%) and to decrease (by 20%) the L-HIS-induced elevation of HI content in the rat brain. Tricyclic antidepressant drugs amitriptyline and imipramine (each 5 and 30 mg/kg ip) had practically no effect on brain HI level in rats without loading with L-HIS, as well as in rats receiving the amino acid.
D000818:Animals; D000929:Antidepressive Agents, Tricyclic / Q000494:pharmacology*; D001923:Brain Chemistry / Q000187:drug effects*; D005260:Female; D006632:Histamine / Q000032:analysis* / Q000378:metabolism; D006634:Histamine H1 Antagonists / Q000494:pharmacology*; D006635:Histamine H2 Antagonists / Q000494:pharmacology*; D006637:Histamine N-Methyltransferase / Q000032:analysis; D006639:Histidine / Q000494:pharmacology*; D006640:Histidine Decarboxylase / Q000032:analysis; D051381:Rats
D000929:Antidepressive Agents, Tricyclic; D006634:Histamine H1 Antagonists; D006635:Histamine H2 Antagonists; D006639:Histidine; D006632:Histamine; D006637:Histamine N-Methyltransferase; D006640:Histidine Decarboxylase