Abnormal maturation of elastic fibres in the atherosclerotic intima.

It is probable that the conditions obtaining during cellular proliferation occurring as a result of damage to the vessel wall will not be at optimum level. The amino oxidase, lysyl oxidase, is copper-dependent and is required for proper cross-linkage in the maturing fibre. Elastic tissue in blood vessels is normally produced by smooth muscle cells and in circumstances where other cells derived from the blood are involved the production of fibres and ground substance may be altered. Orcein staining alone, or after oxidation with oxone, shows different tinctorial affinities for the fibres in the thickened intima and may indicate some departure from normality in their make-up.