抄録
The efficacy of thromboxane synthetase inhibitor in the prevention of cerebral vasospasm after subarachnoid hemorrhage (SAH) was evaluated in a prolonged experiment using dogs. Changes in the diameter of the basilar artery were followed by angiography and morphological changes were studied by photomicroscopy and electron microscopy. As a thromboxane synthetase inhibitor, OKY-1581 (sodium (E)-3-(4(-3-pyridylmethyl)phenyl-2-methylate) was used.
After subarachnoid blood injection, dogs received intravenous injections of OKY-1581 until sacrifice four days after induction of SAH. The control dogs received subarachnoid blood injection without treatment with OKY-1581.
Angiographical examination revealed that the late spasm was almost completely abolished by the treatment with OKY-1581. The early spasm was also prevented, but the drug's effect was less prominent than it was on the late spasm. Morphological study revealed degenerative changes in the endothelium and myonecrotic changes in tunica media following SAH in the basilar arteries of the treated as well as the untreated dogs. However, corrugation of the internal elastic lamina was almost completely absent in the treated dogs.
The above results indicate that a disproportionate synthesis of thromboxane A2 plays an important role in the evolution of chronic cerebral vasospasm following SAH and that drugs such as OKY-1581 that selectively inhibit thromboxane synthetase might be useful in the prevention of vasospasm.
