Caffeine-induced increase of adenosine deaminase activity in mammalian lymphoid organs.

Adenosine deaminase (ADA) activity was increased in spleen and thymus of rat with single and multiple caffeine treatments (10 and 20 mg/kg/day). The stimulation was greater at the higher dose. ADA activity of liver was not affected under these conditions. This study indicates that caffeine may potentiate immunity with the modulation of adenosinergic system through increasing splenic and thymic ADA activity.