The adverse effects of exercise and supraphysiological dose of testosterone-enanthate (TE) on exploratory activity in...

The aim of this study was the estimation of effects induced by chronic administration of supraphysiological dose of TE and prolonged exercise in male rats on anxiety levels (alterations in exploratory activity patterns in EPM).

Two sedentary (control - C and testosterone-enanthate - T) and two exercise (exercise - E and testosterone-enanthate plus exercise - T+E) groups (n=32) underwent adequate protocols - the swimming protocol (1 h/day) and TE (20 mg/kg/w, s.c.) for six weeks. Testing was performed in EPM.

Anxiolytic effects of exercise were manifested as increased exploratory activity in EPM - increase in cumulative duration in open arms, the number of rearings and head-dippings, and TEA. Supraphysiological dose of TE decreased the number of rearings and head-dippings, cumulative duration in open arms and TEA compared to the control group, while this effect of TE was more pronounced compared to the exercise group. The applied dose of TE attenuated beneficial effects of exercise by means of all estimated parameters.

Our results confirmed the beneficial effect of exercise on anxiety levels observed in EPM by means of parameters considering the alterations in exploratory activity. Supraphysiological dose of TE resulted in anxiogenic-like behavior in EPM. The effect of TE was so pronounced that the beneficial effect of exercise was reversed to the control values (or even below them). Based on the results of this trial, we propose that use of the TEA (a new parameter for overall exploratory activity) can improve the evaluation of EPM test results.