Single doses of para-halogenated amphetamines (p-fluoro-amphetamine, p-chloro- and p-bromo-methylamphetamine) selectively inhibit the neuronal reuptake (synaptosomal uptake) of serotonin (5-HT), while amphetamine (A) and methylamphetamine (MA) in subtoxic doses are almost ineffective on this process. The uptake of dopamine (DA) and noradrenaline (NA) is less effectively influenced with the halogenated amphetamines. Among the compounds involved into our studies A was more potent in inhibiting the synaptosomal uptake of DA. p-Bromo-MA (V-111) also decreases the content of 5-HT in the brain and its depleting effect is significantly less pronounced in the brain stem than in the brain hemispheres. Turnover studies revealed that V-111 potently inhibits the rate of 5-HT synthesis in the brain hemispheres, rich in nerve endings, but influences less remarkably its formation in the brain stem, containing mostly perikarya and their axons. The stereoisomers of V-111 were found to be equally effective to inhibit both the uptake and the synthesis of 5-HT, while the (+) isomer influenced more potently the uptake of NA and DA. Subchronic administration of V-111 induced faster regeneration of the long-lasting inhibition of the uptake process of 5-HT and DA. The inhibited activity of tryptophan-5-hydroxylase was also sooner recovered during this kind of V-111 treatment. The continuous administration of V-111 to rats induces faster demthylation of the substance itself. It is supposed that the faster regeneration of the amine uptake and the synthesis of 5-HT experienced in rats during subchronic treatment with V-111 can partly be based on the induced metabolism of the substance.
|Number of pages||9|
|Journal||Polish journal of pharmacology and pharmacy|
|Publication status||Published - Dec 1 1978|
ASJC Scopus subject areas
- Pharmaceutical Science