Accelerated healing in the absence of male gonadal steroids. (a) Left and central panels show macroscopic and histological day 5 wounds illustrating the smaller (healed) wounds in castrated animals compared with intact animals. Collagen content was markedly increased in the wounds of the castrated animals at day 5 (right panels). Magnification: ×10 (center, hematoxylin and eosin); ×20 (right, picrosirius red). (b) Cross-sectional wound areas were significantly reduced on days 3 and 7 after wounding in the castrated animals (n = 6–8 per group; *P < 0.05). (c) Hydroxyproline levels in wound tissue were significantly increased in the castrated mice compared with intact mice at days 5 and 21 after wounding. Extraction and analysis were performed on individual wounds from five mice per group at day 5, and on five samples of pooled wounds (three wounds per tube) at day 21 after wounding. Data represent mean value per 10 mg tissue. *P < 0.05.