雌二醇对皮瓣缺血再灌注损伤组织形态学的影响

The influence of estradiol on histomorphology of skin flaps with ischemia reperfusion injury

目的探索雌二醇对大鼠皮瓣缺血再灌注损伤组织形态学的影响及其可能机制。方法取12～14周龄雄性健康Wistar大鼠48只，随机分为对照组（Ⅰ组）、缺血再灌注组（Ⅱ组）、生理盐水组（Ⅲ组）、雌二醇组（Ⅳ组），每组12只大鼠，制作皮瓣缺血再灌注损伤模型。术后7d，测定皮瓣存活率；检测腹壁浅静脉血清中性粒细胞浓度；切取皮瓣远端组织，在光镜、电镜下观察组织形态学变化。结果术后7d，皮瓣存活率Ⅳ组显著高于Ⅱ、Ⅲ组（P〈0．05）。Ⅳ组腹壁浅静脉血清中性粒细胞浓度明显低于Ⅱ、Ⅲ组（P〈0．05）。光镜下观察：Ⅰ组皮瓣组织结构正常，无明显变化；Ⅱ、Ⅲ组皮瓣皮下疏松结缔组织层水肿明显，有大量中性粒细胞浸润；Ⅳ组皮瓣组织水肿程度轻，组织内炎性反应明显轻于Ⅱ、Ⅲ组。电镜下观察：Ⅰ组皮瓣中性粒细胞结构完整，胶原纤维排列规则；Ⅱ、Ⅲ组皮瓣胶原纤维排列紊乱，中性粒细胞内部分细胞器结构消失，有溶酶体形成Ⅳ组皮瓣内部分中性粒细胞胞质肿胀，有少量凋亡小体形成，但细胞结构完整。结论雌二醇能够抑制皮瓣内中性粒细胞介导的炎症级联反应，减轻缺血再灌注损伤皮瓣中组织结构的病理改变，提高皮瓣存活率。

Objective To study the influence of estradiol on histomorphology of skin flaps with ischemia reperfusion injury. Methods 48 adult male Wistar rats aged 12 - 14 weeks old, were randomly divided into control group （ group Ⅰ ） , ischemia-reperfusion group （ group Ⅱ ） , saline group （ group Ⅲ ） , estradiol group （ group Ⅳ ）. Superficial epigastric artery axial flap, 3 cm ×6 cm in size, was made in the left lower quadrant abdominal of each rat. Flap model with ischemia-reperfusion injury was established by using the nondestructive micro vascular clamp to clamp the superficial epigastric artery. The general condition of the flap was observed after operation. At 7 days after operation,the survival rate of the flap was detected, the flaps were harvested to receive histology and uhrastructural observation. The neutrophils level of the superficial epigastric vein were tested. Results 7 days after operation, the survival rate of the flap in groupⅣ was significantly higher than that in group Ⅱ ,Ⅲ （P 〈 0. 05）. The neutrophils level in group Ⅳ was lower than that in group Ⅱ , Ⅲ （P 〈 0. 05）. The histological observation showed that the degree of tissue swelling and inflammatory exudation in groupⅣ was more slight than that in group Ⅱ, Ⅲ. Presence of high neutrophils density were observed in group Ⅱ, Ⅲ, while slight inflammation and necrosis were observed in groupⅣ. In group Ⅰ , collagen fibers in flap are regularly arranged with no significant necrosis. Oganelles structure disappeared and apoptotic bodies were shown in group Ⅱ and group Ⅲ, even the lysosome could be seen in the cell. Collagen fibers in flap are regularly arranged with slight swelling and no obvious ultrastructural necrocytosis was seen in the cell of group Ⅳ. Conclusion The estradiol can significantly increase flap survival rate by inhibiting neutrophils infiltration and improving the pathological changes of organization structure in flap.