An investigation into the roles of synaptic vesicular Mg++-ATPase in neurotransmitter release, using benzhydryl piperazines.

A series of benzhydryl piperazines was found to inhibit synaptic vesicular Mg++-ATPase. These compounds were also found to increase basal and evoked release of noradrenaline from synaptosomes. A comparison was made between the concentrations effective in inhibiting the enzyme and promoting noradrenaline release. In general, as the degree of Mg++-ATPase inhibition increased, noradrenaline release was increased. The relevance of these findings to a possible role of Mg++-ATPase in noradrenaline release is discussed.