Objective    To measure the collagen content in the granulation tissue of skin wound surface in rats with depression in order to explore the possible mechanism about depression to wound healing.     Methods    Totally 126 Sprague-Dawley rats were randomly and equally allocated to 3 groups:  simple wound group

depression plus wound group

wound plus depression group. Unpredictable stimuli

including fasting

electrocution

water deprivation

swimming in cold water and others

were performed for 18 d to establish depression model of rats. A full-thickness dermal wound (2.2 cm in diameter ) was made on the back of rats to build wound model. Rats from depression plus wound group received 18 days’ stimuli and then wound cutting. For those of wound plus depression

stimuli were carried out from the next day of wounding. The basal tissue in the center of the wound was taken out from 6 rats of every group in 3

5

7

10

14

18 and 21 d after wounding. Hydroxyproline reagent kit was used to detect the content of hydroxyproline in collected tissue. Wound collagen depositions in every time point were stained by nitroxanthic acid sirius red and then observed by polarization microscopy.     Results    Hydroxyproline content and collagen deposition in wound granulation tissue of depression plus wound group rats were lower than those in the other 2 groups. From 18 d after wounding

rats of depression plus wound group had a tendency to the same level as wound plus depression group.      Conclusion    Depression plus wound significantly decreases hydroxyproline synthesis

reduces collagen deposition in wound

and then delays the wound healing.