Yang Mei, Angel Michael F, Pang Yi, Angel John J, Wang Zhe, Neumeister Michael W, Wetter Nathan, Zhang Feng
Division of Plastic Surgery, Southern Illinois University School of Medicine, Springfield, IL USA.
Hand (N Y). 2012 Sep;7(3):297-302. doi: 10.1007/s11552-012-9423-3.
BACKGROUND/OBJECTIVE: Preconditioning has been considered promising for the treatment of ischemic flaps. In this study, the therapeutic effect of postconditioning was compared with that of preconditioning during ischemia/reperfusion (I/R) injury, and a role of inducible nitric oxide synthase (iNOS) in postconditioning treatment was also explored.
Sixty rats were randomly divided into four groups with 15 rats in each group. Ischemic injury was induced in a rat's gracilis muscle flap model. Preconditioning and postconditioning were performed respectively on the flaps in the pre-con group and the post-con group. No treatment was given to the flaps in the control group, and flaps without I/R injury were used as a sham control. Muscle viability ratio, histology, and gene expression of iNOS were examined at different time intervals (3, 12, and 18 h).
A significantly higher survival ratio was observed in both the pre-con group (78.98 ± 3.39, 62.74 ± 3.7, and 54.42 ± 4.45 %) and the post-con group (77.42 ± 4.14, 59.74 ± 6.67, and 49.52 ± 4.13 %) than the control group (45.22 ± 3.69, 42.44 ± 3.76, and 33.2 ± 3.29 %) at 3, 12, and 18 h postoperatively (P < 0.05). There was no statistical difference between the pre-con group and the post-con group (P > 0.05). Histological examination showed delayed and attenuated tissue damage in both the pre-con group and the post-con group when compared to that of the control group. A higher expression of iNOS was observed in both the pre-con group and the post-con group than the control group and the sham group (P < 0.05).
Significant improvement of flap survival could be achieved by both preconditioning and postconditioning treatments; however, better protection could be provided by preconditioning. The higher expression of iNOS may play an important role in the therapeutic effect of postconditioning during I/R injury.
背景/目的：预处理被认为是治疗缺血皮瓣的一种有前景的方法。在本研究中，比较了缺血/再灌注（I/R）损伤期间后处理与预处理的治疗效果，并探讨了诱导型一氧化氮合酶（iNOS）在后处理治疗中的作用。
将60只大鼠随机分为四组，每组15只。在大鼠股薄肌皮瓣模型中诱导缺血损伤。分别对预处理组和后处理组的皮瓣进行预处理和后处理。对照组的皮瓣不做处理，将未经历I/R损伤的皮瓣作为假手术对照。在不同时间间隔（3、12和18小时）检查肌肉活力比率、组织学和iNOS的基因表达。
术后3、12和18小时，预处理组（78.98±3.39、62.74±3.7和54.42±4.45%）和后处理组（77.42±4.14、59.74±6.67和49.52±4.13%）的存活率均显著高于对照组（45.22±3.69、42.44±3.76和33.2±3.29%）（P<0.05）。预处理组和后处理组之间无统计学差异（P>0.05）。组织学检查显示，与对照组相比，预处理组和后处理组的组织损伤延迟且减轻。预处理组和后处理组的iNOS表达均高于对照组和假手术组（P<0.05）。
预处理和后处理均可显著提高皮瓣存活率；然而，预处理能提供更好的保护。iNOS的高表达可能在I/R损伤期间后处理的治疗效果中起重要作用。
