Hypervolemic hemodilution may protect the rat's striatal neurons from ischemic injury by reducing the extracellular dopamine.

In vivo voltammetry (IVV) was used in rats with transient brain ischemia to measure changes in extracellular concentrations of dopamine (DA) and its metabolites in the corpus striatum. Striatal neuronal damage were also rated on a scale of 0-3 (0 = no damage; 3 = maximum cell loss). The striatal extracellular levels of DA and its metabolites increased by 12-fold during the 30 min of brain ischemia and returned to control values at 30 min after reperfusion. In another group treated with 4-5 ml of 10% human albumin intravenously infused 30 min before brain ischemia, both augmented striatal DA (and its metabolites) levels and striatal neuronal damages were reduced as compared to the ischemic control group (P < 0.05, unpaired Student's t-test). These results suggest that hypervolemic hemodilution protects the striatal neurons from ischemic injury by reducing the extracellular striatal DA release in rats.