Accelerated wound repair in old deer mice (Peromyscus maniculatus) and white-footed mice (Peromyscus leucopus)

The closure of bilateral full thickness cutaneous wounds, made over the back with a sharp paper punch, was measured and assessed histologically in outbred deer mice (Peromyscus maniculatus) and white-footed mice (Peromyscus leucopus). In contrast to inbred C57BL/6J laboratory mice (Mus musculus), in which the rate of wound repair was more rapid in young than in mature or aged mice (Cohen et al., 1987), wound repair in Peromyscus was most rapid in aged animals. Aged Peromyscus (45 to 70 months) achieved 50% closure of cutaneous wounds within 3 to 4 days, whereas mature (23 or 24 months) and young Peromyscus required 5 to 7.7 days to reach the 50% closure level. Histologic indices were compatible with the more rapid rate of closure of the cutaneous wounds in aged Peromyscus. The reasons for the unexpected increase in the rate of wound repair with increasing age in Peromyscus are not clear but stress-related hormonal and cellular factors may play an important role.