Inhibition of adenosine kinase and adenosine uptake in guinea-pig CNS tissue by halogenated tubercidin analogues.

Two halogenated analogues of tubercidin (7-deazaadenosine) viz. 5-iodotubercidin and 5'-deoxy-5-iodotubercidin, previously were shown to be potent inhibitors of guinea-pig brain adenosine kinase activity and adenosine uptake in guinea-pig cerebral cortex slices. A further series of halogenated tubercidin analogues have been investigated; of the 9 compounds tested, 5'-deoxy-5-iodotubercidin was the most potent adenosine kinase inhibitor while 5-iodotubercidin was the most potent in inhibiting the facilitated uptake of adenosine. These compounds may be useful for elucidating the involvement of adenosine kinase in adenosine uptake, the maintenance of intracellular adenosine levels and in the neuromodulatory actions of adenosine in the CNS.