The role of adenosine triphosphatases (ATPases) in neurotransmitter release was studied using nerve terminals (synaptosomes) prepared from rat cerebral cortex as a model. Amitriptyline, nortriptyline, protriptyline, desipramine and imipramine were found to inhibit ATPases at concentrations of 10-5 (M) and above. The drugs inhibited both the basal and electrically evoked release of acetylcholine (ACh) and noradrenaline (NA) at concentrations of 10-4 (M) and above. At low concentrations of antidepressants (10-8 and 10-7 M) release of NA was enhanced but there was no affect on ACh release. Other drugs which inhibit Na+, K+-ATPase increased basal NA release as did drugs which inhibited vesicular Mg2+-ATPase. A model is proposed suggesting that transmitter release/re-uptake depends on (1) active Na+, K+-ATPase at the presynaptic membrane and (2) an active synaptic vesicular Mg2+-ATPase.
|Number of pages||11|
|Journal||British Journal of Pharmacology|
|Publication status||Published - 1980|