| Abstract: | 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. |
