✓ The relationship between cerebral blood flow (CBF) and cerebral metabolic rate of glucose (CMR gl) in the white matter was studied in a plasma infusion model of vasogenic edema in cats. Local CBF, as determined by iodoantipyrine testing, was found to be significantly decreased in edematous white matter (mean ± standard error of the mean: 17.3 ± 1.5 ml/100 gm/min) when compared with CBF in the contralateral control white matter (24.8 ± 1.8 ml/100 gm/min). When the values for edematous brain were corrected for dilution, however, the local CBF averaged 25.3 ± 1.7 ml/100 gm/min, which was similar to the control value.
Local CMRgl was found to be significantly increased in plasma-infused white matter (16.3 ± 2.2 µmol/100 gm/min) compared with that in control white matter (10.7 ± 1.3 µmol/100 gm/min). This difference remained, despite correction for dilution and recalculation of local CMRgl values based on altered kinetic constants found in edematous brain. A similar increase in local CMRgl was noted with saline-infusion edema. It is concluded that the increased tissue water level does not alter CBF, but does induce an increase in anaerobic metabolism.