Blood
glutamate scavengers have been shown to effectively reduce blood
glutamate concentrations and improve neurological outcome after
traumatic brain injury and
stroke in rats. This study investigates the efficacy of blood
glutamate scavengers
oxaloacetate and
pyruvate in the treatment of
subarachnoid hemorrhage (SAH) in rats. Isotonic saline, 250 mg/kg
oxaloacetate, or 125 mg/kg
pyruvate was injected intravenously in 60 rats, 60 minutes after induction of SAH at a rate of 0.1 ml/100 g/min for 30 minutes. There were 20 additional rats that were used as a
sham-operated group. Blood samples were collected at baseline and 90 minutes after SAH. Neurological performance was assessed at 24 h after SAH. In half of the rats,
glutamate concentrations in the cerebrospinal fluid were measured 24 h after SAH. For the remaining half, the blood brain barrier permeability in the frontal and parieto-occipital lobes was measured 48 h after SAH. Blood
glutamate levels were reduced in rats treated with
oxaloacetate or
pyruvate at 90 minutes after SAH (p < 0.001). Cerebrospinal fluid
glutamate was reduced in rats treated with
pyruvate (p < 0.05). Neurological performance was significantly improved in rats treated with
oxaloacetate (p < 0.05) or
pyruvate (p < 0.01). The breakdown of the blood brain barrier was reduced in the frontal lobe in rats treated with
pyruvate (p < 0.05) and in the parieto-occipital lobes in rats treated with either
pyruvate (p < 0.01) or
oxaloacetate (p < 0.01). This study demonstrates the effectiveness of blood
glutamate scavengers
oxaloacetate and
pyruvate as a therapeutic neuroprotective strategy in a rat model of SAH.