Ageing is associated with a stiffening of large arteries and an accumulation of calcium on medial elastic fibres (elastocalcinosis); the process is more pronounced in humans than in other mammals. It could constitute a new target for the therapeutics of vascular ageing. A model of human artery elastocalcinosis can be produced by treating young rats with vitarnin D and nicotine (VDN); two dimensional histomorphometry reveals deposition of calcium on medial elastic fibres and fragmentation of the latter.
These studies will be extended using fluorescence confocal microscopy to evaluate quantitative changes in the 3-dimensional organisation of the elastic network. The extent of rupture of the elastic network will be compared to biochemical evaluation of desmosine - a cross-linking amino acid specific for elastin - in the aortic wall. Other models (old SHR rat, domesticated and wild carnivores of various ages, human arteries from autopsy) will also be studied.