Benzodiazepine inhibition of adenosine uptake is not prevented by benzodiazepine antagonists

Uptake of [3H]adenosine into rat cerebral cortex synaptosomes was studied. Hexobendine (10(-5) M) and the benzodiazepine agonists diazepam (10(-5) M) and flurazepam (10(-4) M) significantly inhibited this uptake, but only if the compounds were pre-incubated for 10 min in the case of the benzodiazepines. The benzodiazepine antagonists Ro15-1788 (10(-5) M) and CGS 8216 (10(-5) M) failed to reverse the action of benzodiazepine agonists or hexobendine on [3H]adenosine uptake. The results add weight to the view that inhibition of adenosine uptake processes by benzodiazepines do not contribute to their behavioural effects.