Noninvasive measurement of cerebral blood flow and glucose metabolic rate in the rat with high-resolution animal positron emission tomography (PET): a novel in vivo approach for assessing drug action in the brains of small animals.

The cerebral metabolic rate of glucose (CMRglc) and cerebral blood flow (CBF) in rats were estimated noninvasively with a high-resolution animal positron emission tomography (PET) system that we recently developed. Qualifications of CMRglc and CBF were attempted with radiotracers, 18F-2-fluoro-2-deoxyglucose and 15O-water, respectively. From the data obtained with PET, the CMRglc and CBF values under pretreatment conditions were respectively calculated as 51 +/- 14 mumol/min/100 g and 61 +/- 7 ml/min/100 g under pentobarbital-anesthesia. These values were in close agreement with published data obtained with the autoradiographic technique. Moreover, an increase of 69% (mean) in CBF was detected after i.v. acetazolamide administration. The results indicate that this high-resolution animal PET scanner holds great potential for the assessment of drug-related metabolic and circulatory effects in intact and experimental animals.