Connective Tissue III. Dermal Chemical Response to Age. ∗

Abstract

Summary and conclusions

Although the ground substance of rat skin appeared to decrease with age, dermal insoluble collagen content increased with age. In the face of decreasing concentrations of both total dermal hexosamine and ground substance, there was an abrupt appearance of insoluble hexosamine with age in excess of 200 g body weight. Insoluble non-collagenous protein decreased with increasing body weight until 270 g. With further increases in age, dermal scleroprotein increased until the percent of total non-collagenous protein which was insoluble was essentially the same as that found in 100g rats. The maximum concentration of ground substance, total collagen and scleroprotein were found in the skin of rats weighing 150, 350 and 100g respectively. Maximum concentrations of insoluble hexosamine and insoluble collagen were found in the skin of rats weighing 500 and 270g respectively. The differing effects of aging upon ground substance, insoluble collagen and scleroproteins indicate that different mechanisms, possibly hormonal, were involved in controlling the concentration of each component, and suggest that these materials may be metabolically independent of each other.