[The brain is one of the most important sources of dopamine in general circulation during perinatal ontogenesis in rats].

This study was aimed to test our hypothesis that dopamine synthesized in the neurons of the brain is delivered to the general circulation in rats during prenatal and early postnatal periods, i.e. before the establishment of the blood-brain barrier. Using the high performance liquid chromatography, it was demonstrated that the dopamine concentration and content in the peripheral blood in fetuses and neonatal rats (i.e. before the establishment of the blood-brain barrier) greatly exceeded those in adult rats. Moreover, the establishment of the blood-brain barrier was accompanied by the significant increase of the dopamine concentration in the brain. A drop of the dopamine concentration in fetal plasma after the microsurgical lesion of the forebrain and mesencephalon (encephalectomy) are considered as direct evidence in favour of our hypothesis.