Abstract

Edvaldo Rodrigues de Almeida

The aim of the study presented here was to determine the influence of subcutaneously administered lysine-vasopressin (LVP, 1 U/kg, s.c.), chlorodiazepoxide (BDZ, 20 mg/kg, i.p.), and vehicle (veh, chlorobutanol + saline (0.85%) + Tween 80, 0.1 mL/100 g) administered through the peritoneum on anxiety-related- behavior using the Vogel conflict test, the elevated plus-maze test (EPM) and the marble-burying test. The results of the Vogel test referring to the number of shocks received by rats after administration of vehicle + BDZ was highly significant (p < 0.01), that is, the animals did not show any inhibition during the phase of shock. However, when LVP + BDZ were used the data obtained showed that there was a significant inhibition of BDZ action on the number of shocks received (p > 0.05). In the second phase of the test the veh + BDZ group received a significant number of shocks, benzodiazepine effect and the group receiving LVP + BDZ showed the same result as the vehicle + LVP group (p > 0.05). In the elevated plus-maze (EPM), the group of mice treated with veh + BDZ showed no significant change in their behavior, that is, number of entries and time spent on the open arm was not inhibited (p < 0.01). Already the veh + LVP group has shown inhibition in the number of entries and the time spent on the open arm (p > 0.05). The same result was obtained when the LVP + BDZ group was used in the EPM. In the marble-burying test, the number of marbles hidden was significantly higher in mice treated with the veh + BDZ (p < 0.01). The group treated with veh + LVP presented a small number of hidden spheres (p > 0.05). The data obtained in this study show that LVP in behavioral tests related to anxieties presents an inhibitory action on the BDZ, and the LVP alone does not present any significant effect when compared with the veh (p > 0.05). Veh is the shortened form of vehicle which is the chemical element (solvent) used for dilution of the compound test.