Browsing by Author "NAQUIRA, D"

Now showing 1 - 2 of 2
  • No Thumbnail Available
    Item
  • No Thumbnail Available
    Item
    NICOTINE-INDUCED RELEASE OF CATECHOLAMINES FROM RAT HIPPOCAMPUS AND STRIATUM
    (1978) ARQUEROS, L; NAQUIRA, D; ZUNINO, E
    [3H]Catecholamine release from noradrenergic and dopaminergic neuron terminals of the CNS, induced by nicotine and K depolarization, was studied. Striatal and hippocampal slices of rat brain that incorporated [3H]catecholamines in previous incubations with the radioamines were superfused and stimulated by nicotine and high K. Nicotine produced a marked [3H]catecholamine release from these 2 brain areas, this effect being much greater in the striatum. The time course of radioactive efflux released by nicotine was different from that induced by high K and similar to that evoked by tyramine. Nicotine-induced released was dose dependent, inhibited by low temperature, independent of extracellular Ca and not inhibited by an excess of Mg. Studies with newly synthesized [3H]dopamine and [14C]urea suggested that nicotine acted on the storage vesicles. [3H]catecholamine release was continuous during prolonged nicotine stimulation, in contrast to the transient efflux induced by prolonged stimulation by K, and additive when the slices were superfused simultaneously with nicotine plus K. Previous nicotine superfusion did not modify the typical K release, and the response to nicotine was also not altered when the slices were exposed previously to high K. The mechanism of nicotine release of catecholamines from central catecholaminergic neuron terminals is discussed.