Lack of influence of histamine H1-, and H2-receptor antagonists on histamine level in rat brain.
The intraperitoneal administration of three antihistaminic drugs of H1 type: mepyramine, diphenyhydramine (each 5 and 30 mg/kg) and danitracen (2 and 10 mg/kg) did not modify histamine level in the rat brain after 2 h. Histamine H2-receptor antagonists: cimetidine (25-250 microgram) and metiamide (100 microgram) given directly into the brain had no significant effect on histamine content after 1.5 h. L-histidine (0.5 g/kg i.p.) increased after 1.5 h histamine level in various experiments by 50-75% above control. All antihistaminic drugs did not change significantly histamine level in the brains of L-histidine-treated rats though a slight but consistent tendency to decrease the L-histidine effect in the group of H2-receptor blocking drugs was observed.
D000818:Animals; 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*; D051381:Rats
D006634:Histamine H1 Antagonists; D006635:Histamine H2 Antagonists; D006632:Histamine