Comparison of the effects of the locomotor activity between theophylline and caffeine in mice

Objective Using video tracking system to compare the effects of the locomotor activity between theophylline and caffeine in mice.Methods The KM mice were treated by theophylline and caffeine(both at 1,3,10,30,100 mg/kg)intraperitoneally respectively.After 10 min,the locomotor activity in the open field was recorded for 2 hours.The locomotor track,the total distance,the distances and distance ratio to total distance in central region were analyzed to evaluate the effects of these drugs on locomotor in mice.Results The mice administrated theophylline and caffeine both increased the total distances,and had similar bell-shaped dose-effect relationship.The distances reached the highest at 30 mg/kg theophylline((311±128)m)and 10 mg/kg caffeine ((279±89)m).The larger doses of caffeine inhibited the activity,and the total distance during 0～0.5 h was significantly decreased at the dose of 100 mg/kg(P＜0.05).Theophylline(30 and 100 mg/kg)and caffeine (30 mg/kg)significantly increased the distance ratio in central region(P＜0.01)and decreased the distance ratio in peripheral region(P＜0.01).Conclusion Theophylline and caffeine increase the total distance and the distance ratio in central region in mice,but have different valency and efficacy. Key words: Behavior; Locomotor activity; Theophylline; Caffeine; Mouse