Wound healing: lost in the male

With age, cuts and grazes take longer to heal, particularly in men. Differences in circulating levels of sex steroids might underlie age- and gender-related variations in wound healing: oestrogens accelerate wound repair by dampening local inflammation; androgens have the opposite effect. Gillian Ashcroft and co-workers now provide new insights into how androgens modulate the inflammatory response during acute wound healing (see p. 722). Castration promotes wound healing in male rats. The authors show that treatment of unneutered male rats with an inhibitor of 5α-reductase, which converts testosterone to 5α-dihydrotestosterone (DHT), mimics this effect, suggesting that DHT is a major inhibitor of wound repair. Other experiments in Smad3^-/- mice indicate that the transforming growth factor (TGF) β signalling intermediate Smad3 mediates the pro-inflammatory effects of androgens. The authors suggest that inhibition of DHT production could speed wound healing in elderly males and speculate that measurements of circulating DHT might identify elderly male patients at most risk of developing chronic non-healing ulcers.