Effect of histamine H1- and H2-receptor agonists on gamma-aminobutyric acid (GABA) content in hypothalamus and striatum of the rat brain.
The intraventricular administration of histamine in a dose of 500 microgram, and two histamine H2-receptor agonists i.e. 50-250 microgram of dimaprit and 100 microgram of 4-methylhistamine decreased GABA level after 30 min (by approximately 20%) in the hypothalamus, but not in the striatum of the rat brain. The level of GABA was significantly reduced by 100 microgram of dimaprit after 2 h. Drugs selectively stimulating histamine H1-receptor (100 microgram) did not significantly change GABA concentration of the rat hypothalamus. The results suggest the existence of an H2-receptor--mediated histamine--GABA interaction in the rat hypothalamus.
D000818:Animals; D001923:Brain Chemistry / Q000187:drug effects*; D003342:Corpus Striatum / Q000032:analysis; D017259:Dimaprit; D005260:Female; D006632:Histamine / Q000494:pharmacology; D007031:Hypothalamus / Q000032:analysis; D008761:Methylhistamines / Q000494:pharmacology; D051381:Rats; D011968:Receptors, Histamine / Q000502:physiology*; D011969:Receptors, Histamine H1 / Q000502:physiology*; D011970:Receptors, Histamine H2 / Q000502:physiology*; D013890:Thiourea / Q000494:pharmacology; D005680:gamma-Aminobutyric Acid / Q000032:analysis*
D008761:Methylhistamines; D011968:Receptors, Histamine; D011969:Receptors, Histamine H1; D011970:Receptors, Histamine H2; D005680:gamma-Aminobutyric Acid; D006632:Histamine; D013890:Thiourea; D017259:Dimaprit