Effect of GM1 ganglioside after focal cerebral ischemia in halothane-anesthetized cats

The effect of the ganglioside GM1 was studied in a focal cerebral ischemia model in 30 cats consisting of 2 hours of middle cerebral artery occlusion followed by 4 hours of recirculation. The cerebrocortical electrical activity, extracellular potassium activity, and microcirculation indicated by NAD/NADH fluorescence were measured during occlusion as well as during recirculation in the core of the middle cerebral artery territory, while the cerebral metabolic rate for glucose (ICMRgl) was measured at the end of recirculation. The cats were classified into either mildly or moderately severe stroke groups based on the depression of the cerebrocortical electrical activity on the occluded side. Of 12 cats with only a mild stroke, six were administered GM1 intravenously 30 minutes after occlusion, while six cats were not treated. Of 12 cats with a moderate stroke, six were treated and six were left untreated. In six additional cats, only a sham insult was undertaken. In the cats with mild stroke, GM1 treatment significantly increased lCMRgl in the peripheral middle cerebral artery territory compared with the untreated cats; for the six treated cats, lCMRgl was normalized toward the control level, whereas it was depressed in the six untreated cats. There were no other significant effects of GM1 treatment on the other measured parameters. A potential protective effect of anesthesia is discussed.