The B-aminopropionitrile-fed turkey: a model for detecting potential drug action on arterial tissue

Broad-breasted white male turkeys develop hypertension, tachycardia and aortic arteriosclerosis spontaneously by approximately 5 weeks of age. When fed B-aminopropionitrile (BAPN), aortic tensile strengths are lowered, and a high percentage of the turkeys die from aortic dissecting aneurysms. There are essentially no deaths from aneurysms when either dl-propranolol or reserpine is fed in concert with BAPN; practolol and soltalol partially protect the BAPN-fed turkey from lethal aneurysms while hydralazine and phenelzine sulphate potentiate mortality from aneurysms. Dl-propranolol decreases and reserpine increases dP/dtmax and both drugs lower arterial pressure and heart rate when fed with BAPN. Such diets also decrease the ultrastructural disarray of collagenous and elastic fibres in the media of the abdominal aorta that occurs from the feeding of BAPN and thereby raise aortic tensile strength. Sotalol and practolol when fed to BAPN-fed turkeys lower blood pressure and dP/dtmax, but neither drug affects aortic tensile strength and both counteract the deleterious effect of BAPN on the ultrastructure of collagenous and elastic fibres to a minor degree. Phenelzine sulphate does not affect arterial pressure while hydralazine reduces arterial pressure; both drugs decrease aortic tensile strength and increase the ultrastructural disruption of aortic elastin and collagen in the BAPN turkey. The results suggest that dl-propranolol, reserpine, phenelzine sulphate, and hydralazine have an action on aortic tissue and indicate the usefulness of the BAPN-fed turkey as a model for identifying potential drug effects on aortic elastin and collagen.