Effects of Caffeine and Theophylline on Activity of Rats in Relation to Brain Xanthine Concentrations 1

Abstract

Summary

Caffeine and theophylline were equally effective in increasing confinement motor activity when administered ip in doses up to 0.10–0.12 mmole/kg. Higher doses of caffeine produced some toxicity as evident from less stimulation of motor activity. Theophylline produced its peak effect at a dose of 0.17 mmole/kg (30 mg/kg). Doses of either xanthine as great as 0.25 mmole/kg produced much less activity than the optimum doses. Equimolecular doses of caffeine and theophylline produced approximately equal brain xanthine levels.