Blood flow and metabolism in vasogenic oedema.

The relationship between white matter cerebral blood flow (CBF) and glucose metabolism (LCMRgl) was studied in a plasma infusion model of vasogenic oedema in cats. LCBF as determined by iodoantipyrine was found to be significantly decreased in oedematous white matter (17.3 +/- 1.5 ml/100 gm/min) when compared with contralateral control white matter (24.8 +/- 1.8 ml/100 gm/min). If the values for oedematous brain were corrected for dilution, however, the LCBF averaged 25.3 +/- 1.7 ml/100 gm/min, which was the same as control. LCMRgl was found to be significantly increased in plasma-infused white matter (16.3 +/- 2.2 mumol/100 gm/min), compared with control white matter (10.7 +/- 1.3). This difference remained despite correction for dilution and recalculation of LCMRgl values based on altered kinetic constants found in oedematous brain. A similar increase in LCMRgl was noted with saline infusion oedema. It is concluded that increased tissue water does not alter CBF, but does induce an increase in anaerobic metabolism.