The xanthine derivatives and cerebral blood flow (CBF) after i.v. or i.c. administration in SHR rats.

It was shown, that TPH after i.v. administration causes significant decrease of CBF, but IBMX and P-23 had no effects on CBF. After i.c. administration of TPH and P-23 CBF decreased, whereas IBMX i.c. injection had no effect on CBF in SHR rats. These results indicate that direct administration of TPH or P-23 into the cerebral vascular beds causes intensification of TPH activity and reveals the action of P-23. These data suggest, that intracarotid administration of xanthine derivatives can change their cerebrovascular activity.