Comparison of effects of Idazoxan and 5-HTP on anxiety with Chlordiazepoxide

Abstract

We studied the effect of the selective alha-2 adrenoceptor blocker idazoxan and precursor serotonin (5-HTP) on anxiety-related behavior in rats. The conflict drinking test, and evaluator plus-maze were used as model. Idazoxan (2 mg/kg) showed an anticonflict effect, having doses dependently increased the number of punished lickes. 5-HTP showed that anxiolytic-like effect in both models. This drug reversed action and produced anxiogenic-like effect at high doses. In contrast, arecholine which is a cholinergic muscarinic agonist drug, produced anxiogenic-like behavior. At 2 mg/kg increased number of entrance (OE) and using time (OT) in open arms in montgomery's test. Anxiolytic-like effect of this drug was less than of chlordizepoxide. These results showed that increase release of noradrenaline in synaptic nerve terminals of neurons produced anxiety-related behavior. While high release of serotonin in this area reduced behaviors disorder in rats.