The aim of this study was to assess the effect of endothelial dysfunction caused by a decrease in the estrogen level on the severity of cerebral ischemia.
 Methods. Endothelial dysfunction was caused by extirpation of the uterus with appendages and was confirmed by counting circulating endothelial cells and evaluating stimulated and basal secretion of nitric oxide. Focal cerebral ischemia was modeled by intravasal occlusion of the middle cerebral artery. The severity of ischemia was assessed according to the scales of neurological deficit (Combs & D’Alecy and McGraw), in the Rotarod test and in terms of the volume of necrosis.
 Results. Estrogen deficiency resulted in an increase in the circulating endothelial cells by 88%, as well as a decrease in stimulated and basal nitric oxide secretion by 17.1% and 14.7% respectively. Focal cerebral ischemia in animals with endothelial dysfunction caused by estrogen deficiency resulted in greater cerebral damage, resulting in an increase in the level of neurological deficit on the Combs & D’Alecy and McGraw scales for 7 days, a decrease in the retention time on the rotating rod by 32%, as well as an increase in the infarct volume by 89% relative to the group of animals without sexual hormones failure.
 Conclusion. It has been shown that endothelial dysfunction caused by estrogen deficiency complicates the severity of cerebral ischemia, causing a more pronounced neurological and motor deficit, and contributes to an increase in the size of infarct volume.