Influence of age, treatment with corticosteroids and strain rate on mechanical properties of rat skin

Abstract

The mechanical properties (ultimate extension, load to failure, tensile strength and elasticity module) of rat skin strips were measured at various strain rates ranging from very low creeping rates (5 · 10 −3 cm/min) to speeds approximating free fall from a height of 1.3 m (3 · 10 4 cm/min). Skin specimens of young (10 weeks old), aged (2 years old) and young rats treated with prednisolone acetate were studied simultaneously. No influence of extension rate on strain to failure was found. Load to failure and tensile strength, however, were positively correlated to the logarithm of strain rate. At each rate of extension the tensile strength of specimen from rats treated with prednisolone acetate was higher than those of controls. The values of skin strips from aged animals showing the same dependence on strain rate were still higher. In young and in prednisolone-treated rats the elasticity module exhibited a definite linear dependence on the logarithm of extension rate. In old rats the elasticity module increased only from low to medium rates of extension. At higher strain rates only a small increase was found. The meaning of these results is discussed.