Modification of collagenase activity in the skin of young, adult and old rats by a plasma factor

Abstract

After its stabilization during aging, collagen undergoes a certain degradation by collagenase action. Denatured collagen is degraded very fast, and that of old animals faster than that of young ones. The process is well regulated, the degradation emits signals to the cells for a new synthesis of collagen. In newly synthesized collagen the crosslinking has to begin again, therefore we may consider this collagen a "young" one. Influences upon the dermis collagen, for instance, can have an age-accelerating or-delaying effect. We put forward the question, if the possibility exists to induce the synthesis of new collagen by the action of collagenase. To do this it might be necessary to boost collagenase action using stimulators or activators, as there are for instance cytokines that are perhaps the most physiologically relevant mediators to simulate the production of collagenase. Other compounds possibly activate the already produced enzyme. We tested a bovine (calf) serum protein that is heat resistant (AB) for its activity to stimulate collagenase in vitro using the collagenase activity of homogenized skin to estimate the necessary concentrations for the stimulation in vivo. For that purpose we used H-3 labelled collagen in a system with and without the activator in various concentration.. After finding the appropriate concentration of the activator, tested with the dermis of rats aged 14 and 32 months, the shaved back skin of rats aged 9 and 21 months was treated with the activator during a time of four weeks using this concentration. As compared with the controls the dermis showed biochemical and rheological characteristics corresponding to the dermis of younger rats. We conclude that the bovine serum protein activates collagenase to such a degree that collagen turnover is vigorously accelerated. Furthermore it was also possible to cancel UV induced crosslinking of collagen in rats. Both effects might have a certain importance with respect to skin treatment.