Studies on the Metabolism of D- and L-Isomers of 3,4-Dihydroxyphenylalanine (DOPA). I. Autoradiographic Study on the Distribution of ^<14>C-Labeled D-and L-DOPA and Dopamine after Intravenous Administration in Rats

概要

論文の詳細を見る
The distribution of D- and L-^<14>C-DOPA and ^<14>C-dopamine were investigated by means of whole-body autoradiographic technique following intravenous injection in rats. Significant differences were found in the distribution pattern of radioactivity between the two isomers, as summarized in the following : i) a rapid and marked uptake of L-DOPA by the brain and the localization in the caudate nucleus, in contrast to a slow and a very low distribution of D-DOPA over the whole brain, ii) an extremely high uptake and a long retention of L-DOPA in the adrenal medulla, iii) a much higher concentration of L-DOPA in the skeletal muscle and liver than D-DOPA, and an appreciably faster initial rate of elimination of D-DOPA into the urine, and iv) an accumulation and a long retention of both isomers in the pancreas, renal medulla and hair follicles, with an appreciably higher concentration in the D-isomer. ^<14>C-Dopamine did not show any radioactivity in the brain, confirming that it cannot pass through the blood-brain barrier. These results were discussed in relation to the possible differences in their metabolism and transport and to the therapeutic effect of L-DOPA against Parkinsonism.
社団法人日本薬学会の論文
1971-12-25