Changes in mechanical properties, thermal stability, reducible cross-links and glycosyl-lysines in rat skin induced by corticosteroid treatment

Abstract
The effects of systemic cortisol treatment on the biophysical and biochemical properties of skin were investigated. Rats were injected s.c. with cortisol for 14, 60 and 120 days and samples of lumbar skin were studied. Corticosteroids exert a biphasic effect on the strength of skin: a relatively fast increase in the strength and stability, caused by an increased collagen cross-linking, and an inhibited collagen synthesis which ultimately results in a thinning of the skin and a decrease of collagen content consistent with clinical observations. The thermal stability is increased indicating an increased proportion of thermostable cross-links in skin collagen. No changes are observed in the percentage type III collagen with respect to type I collagen. Increased amounts of glucose attached to the .epsilon.-amino group of lysine residues in the collagen are found after long-term treatments, an alteration which may play a role in hampering the tissue functions.