Coronary and thyroid arteriopathy induced by allylamine and β-aminopropionitrile

Broad breasted white male turkeys were fed four different diets: allylamine fumarate (AL), AL plus β-aminopropionitrile (BAPN), BAPN alone, and a control diet. Twice as many turkeys died of internal hemorrhage when fed BAPN and AL, as compared to those fed only BAPN. None fed AL alone or the control diet died. Arterial blood pressure was highest in turkeys fed BAPN or the control diet. Light microscopic lesions of the coronary and thyroid arteries were seen only in turkeys fed BAPN and AL, or AL alone. There was intimal hyperplasia, hypertrophy of medial smooth muscle cells, and hyalinization of vascular walls which did not exhibit intimal hyperplasia. Lesions were more prominent in turkeys fed BAPN and AL. Electron microscopic lesions of the coronary artery also were seen only in turkeys fed BAPN and AL, or AL alone. Intimal hyperplasia was manifested as several rows of smooth muscle cells above the internal elastic membrane. Smooth muscle cells in both the hyperplastic intima and also the tunica media contained closely packed myofilaments and prominent attachment points. Rare medial smooth muscle cells were electron lucent due to mitosis, while others were infrequently electron-opaque because of necrosis. Small arterioles without intimal thickenings had lumens which were almost occluded and their medial smooth muscle cells were edematous. The walls of hyalinized arterioles contained intertwined bundles of striated fibers.