Effects of estrogen on promoting the wound healing of hemorrhagic shock rats by arousing homing of mesenchymal stem cells

Chen Xiaoming; Zhu Yu; Wu Yue; Li Tao; Liu Liangming

doi:10.3969/j.issn.1672-8521.2017.01.003

Abstract：Objective:To investigate the effects of estrogen on promoting wound healing of hemorrhagic shock rats by arousing homing of mesenchymal stem cells (MSCs).Methods:SD rats were used to establish the hemorrhagic shock models by full-thickness skin defect with 2 cm diameter made at each side of dorsal middle line.Ninety-six model rats were randomly divided into 4 groups:sham operation group (intubation in artery and vein,but no bleeding and fluid infusion),hemorrhagic shock group (conventional fluid resuscitation with 2∶1 of lactated Ringer's solution + hydroxyethyl starch),low-dose estrogen group (estrogen 0.2 mg/kg and conventional resuscitation) and high-dose estrogen group (estrogen 0.5 mg/kg and conventional resuscitation).The skin wound healing time,healing rate,tissue blood flow,ATPase activity and the mobilization and homing of MSCs in skin and peripheral blood were observed.Results:Compared with the sham operation group,the skin wound healing was slower in hemorrhagic shock group (P＜0.05),the healing rates were (15.40±0.01)％ on day 4 and (36.80±1.25)％ on day 8,respectively;and the ATPase activity and blood flow decreased significantly (P＜0.01).Estrogen markedly promoted the skin wound healing,obviously improved the tissue blood flow,enhanced the ATPase activity and increased the number of MSCs in damaged skin tissue and blood.In low-dose estrogen group,the skin wound healing rates rose significantly when compared with that in hemorrhagic shock group,but were still lower when compared with that in sham operation group at day 4 [(22.10±0.01)％ vs.(37.10±4.32)％] and day 8 [(46.4±1.25)％ vs.(67.70±1.79)％,P＜0.05],and the number of MSCs in peripheral blood and damaged skin tissues increased significantly.High-dose estrogen showed better effects than low-dose estrogen on promoting wound healing,reached healing rates of (28.40 ± 0.12)％ and (57.3 ± 2.01)％ at day 4 and day 8,respectively,and showed more obviously increase of MSCs in skin wound and peripheral blood.The wound healing time in the hemorrhagic shock group [(23.98±l.56) days] was significantly longer than in the sham operation group [(14.98±1.21) days,P＜0.01],the wound healing time significantly reduced in high-dose estrogen group [(16.87±1.56) days] and low-dose estrogen group [(22.67±1.78) days,P＜0.05],and was the shortest in high-dose estrogen group.Conclusions:Estrogen can mobilize MSCs homing and promote the wound healing of damaged tissues of hemorrhagic shock rats.