[Effects of methamphetamine and a reserpine-like drug on norepinephrine and dopamine metabolism in the rat brain].

Simple and sensitive methods for the separation and determination of catecholamines and their metabolites by thinlayer microcrystalline cellulose chromatography have been developed and applied to the analysis of norepinephrine (NE) and dopamine (DA) metabolism in the brain of Wistar rats given 12C-NE or 14C-DA intraventricularly. 14C-DA in the whole brain declined more rapidly than did 14C-NE. The percentage of unchanged 14C-NE in total radioactivity in the brain of rats administered 14C-NI was high, while on the other hand, the percentage of unchanged 14C-DA in cases of 14C-DA was low. In the metabolism of 14C-DA, the deaminated and O-methylated deaminated metabolites showed transient and delayed temporary rises, respectively. Drugs which affect the metabolism of catecholamines were also examined. Methamphetamine reduced NE, deaminated and O-methylated deaminated metabolites, and markedly elevated normetanephrine in the brain of rats given 14C-NE. Regarding the metabolism of DA, methamphetamine increased 3-methoxytyramine and homovanillic acid and reduced deaminated metabolites, but had no effect on DA and NE. On the other hand, a reserpine-like drug (Ro4-1284) reduced NE and increased deaminated and O-methylated deaminated metabolites in the metabolism of NE, and reduced to a great extent DA and NE and increased homovanillic acid in the metabolism of DA. From these results, it is concluded that the effect of methamphetamine was more evident in NE metabolism than DA, while the effect of Ro4-1284 was more evident in DA metabolism than NE.