Abstract
Protective effects of thiopental, mannitol, and glycerol on global cerebral ischemia were histopathologically investigated.
Global cerebral ischemia was produced as reported previously (Part I). They were divided into four groups: no treatment; thiopental; mannitol; and glycerol-treated groups. Morphological change after ischemia was evaluated by electron microscopy of red blood cells, the luminal surface of the internal carotid artery, and of the cerebral cortex. In animals receiving no treatment, many erythrocytes underwent a shape change from discocytes to echinocytes or sphero-stomatocytes. The luminal surface revealed various “crater-like” defects. Neurones were shrunken with extremely dense cytoplasm containing swollen mitochondria or endoplasmic reticulum and capillary lumina were reduced to a slit. In contrast, in animals treated with thiopental, ischemic change of neurones and luminal surface of the internal carotid artery were minimal. In animals treated with mannitol or glycerol, deformed erythrocytes were less frequent. Capillary lumina remained patent and the swelling of perivascular glial processes was strikingly decreased. Moreover, in animals treated with glycerol, neurones underwent little ischemic change.
It is confirmed that thiopental can protect neurones and can also improve cerebral circulation, and that mannitol or glycerol can improve post-ischemic microcirculatory disturbance.
