The effect of antimigraine preparations on serotonin transport in the brain synaptosomes of rats

: Methisergide and nicergoline act as competitive inhibitors whereas tolfenamic acid as a non-competitive inhibitor of 3H-serotonin accumulation which occurs with the involvement of the high-affinity system of serotonin uptake by the rat brain synaptosomes. Methisergide, nicergoline and tolfenamic acid at concentrations ranging close to Ki value were found to enhance the basal and K(+)-induced release of 3H-serotonin from the rat brain synaptosomes. The findings obtained indicate the ability of the drugs to disturb serotonin transport. In addition, the drugs are likely to exert the depleting effect on serotonin stores in serotoninergic neurons. Picamilon failed to affect either the uptake or the release of serotonin from the rat brain synaptosomes.