Selective destruction of the outer leaflet of the capillary endothelial membrane after intracerebral injection of arachidonic acid in the rat.

A peculiar ultrastructural change of the cytoplasmic membrane is described. It concerns selective destruction of the outer leaflet of the luminal side of the capillary endothelium in the white matter of the rat brain, 30 min and 3 h after intracerebral injection of arachidonic acid (AA). The cristae of the mitochondria disappeared in the endothelium of many capillaries. These changes were observed mainly in the central part of brain edema, where the extracellular space was markedly widened. The possible mechanism whereby these changes developed is discussed.