Propranolol delays the formation of aneurysms in the male blotchy mouse

Propranolol has been reported to prevent aortic aneurysms in the beta-aminoproprionitrile-fed broad-breasted white turkey model. The purpose of this investigation was to determine the effect of propranolol in another animal model of aortic aneurysms, the spontaneously aneurysm-prone Blotchy (BLO) mouse. One hundred fourteen male BLO mice were fed control chow or a diet supplemented with 0.10% (w/w) propranolol. Groups were sacrificed at monthly intervals and the presence of aneurysms was determined after latex injection into the left ventricle. Aortic diameter was also measured at the widest point in a subset of mice from each group sacrificed at 4-5 months of age. At 4 months 86% of control and 32% of propranolol-fed animals had aneurysms (P less than 0.001). The difference in mean aortic diameter was also decreased by 33% in the propranolol-fed group (P less than 0.01). This study suggests that propranolol delays the formation of aneurysms in this spontaneous, genetically determined animal model.