Effects of ethanol- and saline-base PGE1 on the canine cerebral circulation

The effects of ethanol- and saline-base prostaglandin E1 (PGE1) on systemic arterial blood pressure ((ABP), cerebral blood flow (CBF), cerebral vascular resistance (CVR), and cerebrospinal fluid (CSF) pressure were determined in anesthetized dogs. Progressively greater carotid intra-arterial infusions of ethanol-base PGE1 moderately decreased systemic ABP and CVR while perfusion of the CSF system with PGE1 moderately increased ABP and CVR; CBF was unaffected by either route of administration and CSF pressure was constant except for a slight decrease at the lowest intraventricular perfusion rate. Similar infusions of PGE1 were administered in saline base solutions in another group of dogs. Carotid intra-arterial infusion decreased ABP and CBF moderately at the highest infusion rate and caused a transient increase in CSF pressure. Cerebrospinal fluid system perfusion increased ABP moderately but did not affect the other parameters. These data indicate that PGE1 does not have a significant effect on cerebral hemodynamics when infused via the CSF system, but may produce slight cerebral vasodilation when infused into the carotid arteries in an ethanol base. This vasodilation may be due to autoregulation.