Exercise and pharmacological treatment: influence on locomotor activity in SHR rats

Abstract

Restless legs syndrome (RLS) is characterized by abnormal sensations in the lower limbs and negatively impacts on sleep. Dopaminergic agonists (pramipexole, PPX) may be used in the treatment. However, chronic use may cause worsening of symptoms (augmentation). Physical exercise (PE) also may be effective in reducing RLS symptoms and improving the sleep pattern. The main purpose of this study was to evaluate the effect of PPX and acute PE on locomotor activity (RLS symptoms) of spontaneously hypertensive rats (SHR). Animals were distributed into 4 groups: Saline, PPX1 (0.1 mg/kg) at 75 days of age, PPX2 (0.05 mg/kg) at 91 days of age and PPX3 (0.05 mg/kg) at 125 days of age.The animals received a daily injection of PPX or saline (07:00 h) for 48 days. The PE (treadmill) consisted of a single session (30 min) at 20–22 m/min. The evaluation of locomotor activity (open field) was performed at baseline and weekly, after administration of the drug. Both PPX and PE caused changes in locomotor activity (RLS symptoms), on specific days. The groups that received PPX had weight changes when compared with the saline groups, but without manifestation of the augmentation.