[Mechanism of action of piracetam on cerebral circulation].

The experimental data show that piracetam exerts a marked effect on cerebral hemodynamics producing a lowering of cerebral artery tonus and an increase of local blood flow. In addition, an increase of GABA content is noted, particularly following an experimentally-induced disorder of cerebral blood circulation. A stable dilatation of the mean capillary diameter, a decrease of the number of non-functioning capillaries in the brain cortex after piracetam administration indicate an important role of piracetam as a cyclic analogue of GABA in regulation and compensation of disordered cerebral hemodynamics.