Pretreatment with monosialoganglioside GM1 protects the brain of fetal sheep against hypoxic-ischemic injury without causing systemic compromise

The purpose of this study was to determine whether prophylaxis with monosialoganglioside GM1 can protect the fetus from hypoxic-ischemic encephalopathy in utero. Because some protective strategies can compromise the fetus, the effect of GM1 treatment on metabolic status and blood pressure was also evaluated. Chronically instrumented near-term fetal sheep (119-133 d) were subjected to 30 min of severe cerebral ischemia. Six were given 30 mg/kg GM1 through the umbilical vein 2 h before insult followed by continuous infusion of 30 mg/kg/d over the next 60 h, and these were compared with seven vehicle-treated control sheep. The time course of electrocorticographic activity and cytotoxic edema within the parasagittal cortex were determined with real-time spectral analysis and continuous impedance measurements, respectively. Histologic outcome was assessed 72 h later. Pretreatment with GM1 improved recovery of primary edema, reduced the duration of epileptiform activity (15 +/- 2 versus 31 +/- 5 h; p < 0.05) and the magnitude of secondary edema (p < 0.05). At 72 h, histologic damage was reduced, particularly in the cortex (p < 0.05) and hippocampus (p < 0.01), and residual electrocorticographic activity was increased in the GM1-treated group (-5 +/- 1 versus -9 +/- 3 dB, p < 0.01). GM1 infusion did not alter arterial blood pressure or metabolic status. These results indicate that GM1 can protect the fetal brain against hypoxic-ischemic injury without causing hypotension or metabolic compromise.