Experimentally induced cerebral aneurysms in rats: part II.

An experimental condition that permits easy inducement of cerebral aneurysms in rats is reported. Previously, we demonstrated that saccular cerebral aneurysms were inducible in experimental animals and suggested that adult rats might be more preferable for inducing the lesion. Therefore, a longer-term study was performed intending to increase the incidence of cerebral aneurysms, using only adult rats. Adult rats were treated with ligation of one common carotid arter, deoxycorticosterone and salt hypertension, and beta-aminopropionitrile. Cerebral aneurysms developed in eleven of 30 rats which died 11-21 weeks after the start of the beta-aminopropionitrile feeding. All aneurysms were located on the anterior cerebral-anterior communicating arterial complex. Contributory mechanisms are discussed.