Abstract
A cut made into the back skin of either newborn or adult mice evokes, at both ages, a hyperproliferative response in the epidermis. Differences in the reaction of neonatal as compared with adult epidermis are found in the spatial distribution of proliferative activity as well as in its time course. The response in adult mouse epidermis is inhibited by local application of the prostaglandin inhibitor indomethacin, whereas the response of the newborn epidermis is not.