EFFECTS OF INDOMETHACIN ON CEREBRAL BLOOD-FLOW AND OXYGEN-METABOLISM - A POSITRON EMISSION TOMOGRAPHIC INVESTIGATION IN THE ANESTHETIZED BABOON

The aim of this study was to clarify the controversy about the effects of indomethacin on the coupling of cerebral blood flow (CBF) to cereb ral oxygen metabolism (CMRO(2)). CBF, blood volume (CBV), oxygen extra ction fraction (OEF) and CMRO(2) were measured by positron emission to mography (PET) in five anaesthetized baboons before and during an i.v. administration of indomethacin (bolus 20 mg/kg followed by perfusion 10 mg/kg.h). Administration of indomethacin resulted in a marked and h omogenous decrease of CBF in every region analysed (-28% to 40%) and a moderate reduction in CBV (-8% to -16%). In contrast, CMRO(2) display ed a small increase in thalamus and pens (+10% and +13%, respectively) . OEF increased greatly in all structures studied (+59% to +96%). Thes e findings show that the potent cerebrovascular effects of indomethaci n are not related to a decrease in CMRO(2) as measured through the use of PET. Copyright (C) 1996 Elsevier Science Ireland Ltd.