Morphometric analysis of the degradation of human skin elastic fibres by human leukocyte elastase (EC 3-4-21-37) and human skin fibroblast elastase (EC 3-4-24).

The degradation of human skin preelastic fibres (PEF) namely oxytalan and elaunin fibres, and that of mature skin elastic fibres (EF) by human leukocyte elastase and purified human fibroblast elastase was studied by morphometric analysis. Leukocyte elastase hydrolyzed both types of fibres; Elaunin and mature elastic fibres were found particularly sensitive to degradation by this proteinase. Skin PEF and EF from 59-67 yr-old individuals were degraded to a greater extent by this proteinase than those from the two younger individuals analyzed (18 and 24 yrs old). Human skin fibroblast elastase mainly hydrolyzed PEF. It possessed only a limited action toward mature dermal elastic fibres. At the highest dose of proteinase used, the volume fraction of EF was reduced by 50% in youngest skins and by 25% in the oldest ones.