We have studied the influence of bilateral carotid ischemia-reperfusion on the indices of the functional and morphological condition of the vascular endothelium of the brain hypothalamolimbic complex. It has been established that a decrease of the density of endothelial location in an early ischemic-reperfusion period in the control rats has a relative characterstipulated by edema of cells whereas on the 12-th day of observation an increase of the absolute density of cells takes place. During both periods of observation there is an increased content of the tjtal RNA in the capillary endotheliocytes of all the structures. An early reaction of the morpho-functional states of endotheliocytes to ischemic-reperfusion is absent in animal with diabetes mellitus, exept the vessels of the ventromedial hypothalamus while a late one is restricted by a growth content in RNA cells.