Studies of Vascular Ultrastructure in Experimental Subarachnoid hemorrhage

ABSTRACT

Cerebral Vasospasm was produced experimentally by injecting normal cat's blood into the cisterna magna of the cat. Ultrastructural changes were observed sequentially from 24 hours to 15 days following subarachnoid hemorrhage(SAH). Twenty-four hours after SAH, endothelial cells in the intima were round shaped and their cellulrar surface was corrugated, these changes remained to 72 hours after SAH with intimal thickening and loss of tight intercellular junction. But since 7 days after SAH, the endothelial cells assumed a more normal spindle-shaped configuration with tight intercelluar junction and an increase in cytoplasmic filaments and vacuoles. The internal elastic laminae was thickened and somewhat more electron dense than normal. In the media, the smooth muscle cells were most consistently and severely affected showing degeneration of mitochondria, vacuoles containing fine particles and loss of complex internal structure, surrounded by increased amounts of intercellular collagen. These findings concluded that the ultrastructural changes in the cat's basilar arterisl wall observed after induction of subarachnoid hemorrhage with fresh autogenous blood occurred as a consequence of vasospasm.