一氧化氮对任意型皮瓣成活的影响

The effects of nitric oxide on the survival of a random pattern skin flap

目的 观察一氧化氮 (nitricoxide ,NO)对任意型皮瓣成活的影响。方法 采用Wistar大鼠为实验动物 ,在其背部形成 9cm× 3cm任意型皮瓣 ,通过图像分析技术、病理切片、电镜观察、组织化学染色和血清中NO2 - NO3 - 含量的测定等手段 ,观察NO合酶抑制剂 (L NAME)和NO合成前体 (L Arg)对皮瓣成活的影响。结果 术后第 7dL Arg组皮瓣成活率明显高于其他两组 (P <0 0 1)。组织学检查发现L Arg组皮瓣毛细血管扩张及增生明显。结论 促进NO合成能扩张微血管 ,改善微循环 ,提高皮瓣存活率。

Objective To observe the effect of nitric oxide (NO) on the survival of a random pattern skin flap. Methods Caudal based random skin flaps (9cm × 3cm) were raised on the back of Wistar rats. Six methods were used in the experiment to observe the effect of NO synthase inhibitor L-NAME and NO synthase substrate L-arginine on flaps: image analysis technology; light and electron microscopic studies; enzyme histochemistry of NOS in flaps; concentration of NO 2-/NO 3- in plasma and wet/dry ratio of the flap tissue. Results Survival area of flap in the L-arginine-treated group significantly increased (67.06 ± 5.65)% (p<0.01) whereas the area in the L-NAME-treated group significantly decreased (35.17±1.87)% (p<0.01) compared with the control group (53.25 ± 3.24)% at seven days after the operation. General and microscopic observations showed that pathological changes in the L-arginine-treated group were fewer. Abundant capillaries and fewer inflammatory cells were noticed in the L-arginine-treated group. Transmission Electron Microscopy (TEM) studies find endothelial swelling, thrombosis-formation and endothelial loss of contact with the basement membrane in the L-NAME treated group. Before operation, the serum NO concentrations were not significantly different in three groups (p>0.05). After operation, NO concentration of the control group began to increase and reached to the top at the third day. L-Arg kept serum NO concentration in a higher level than the control. Enzyme histochemistry of NOS in flaps: microvessel intima in dermis, hair follicles, sweat glands and inflammatory cells showed oxford blue, more positive in flaps of the L-Arg treated group than the control group at the third day after operation. The flaps of L-NAME- treated group demonstrated negative or weak positive. Wet /dry ratio: twenty-four hours after flap elevation wet/dry weight ratios increased significantly in all regions of the flap of the L-arginine-treated rats compared with saline-treated rats. The ratios of the flaps of L-NAME-treated rats were reduced compared with saline-treated rats. Conclusion NO could improve microcirculation of the flap and increase its survival rates. The mechanism might be that NO could accelerate flap vascularization and protect flaps from ischemia -reperfusion injury.