Lesions caused by copper depletion in the chicken. Light and electron microscopic study.

Lesions of the aorta and other organs of copper depleted layers, roosters, day-old chicks and chick embryos were studied by light- and electron microscopy. Copper deficiency results in late and abnormal development of elastic fibres: inhibition of the formation of cross linkages causes a decline of elastin synthesis. The microfibrils constituting the blackbone of the elastic fibre form a honey-comb pattern. The small amount of amorphous elastin is digestible by elastase, the microfibrils are resistant to the action of the enzyme. The aortic elastic fibres are irregularly shaped, broken revealing a honey-comb like pattern. They maintain an increased affinity to PTA. Tears--dissecting aneurysms--arise in the media, vacuoles appear in the heart muscle, haemorrhages and inflammatory changes may arise in other organs.