Weinzierl Andrea, Coerper Maximilian, Harder Yves, Menger Michael D, Laschke Matthias W
Institute for Clinical and Experimental Surgery, Saarland University, 66421 Homburg, Germany.
Department of Plastic Surgery and Hand Surgery, University Hospital Zurich, 8091 Zurich, Switzerland.
Biomedicines. 2024 Mar 20;12(3):690. doi: 10.3390/biomedicines12030690.
Periodic fasting (PF) as a form of dietary restriction has been shown to induce tissue-protective effects against ischemic injury in several different tissues. Accordingly, in this study we analyzed whether a short-term 24 h fast is suitable to prevent necrosis of musculocutaneous flap tissue undergoing acute persistent ischemia. C57BL/6N mice were randomly divided into a PF group ( = 8) and a control group that was given unrestricted access to standard chow ( = 8). The PF animals underwent a 24 h fast immediately before flap elevation and had unrestricted access to food for the rest of the 10 day observation period. Musculocutaneous flaps with a random pattern design were dissected on the animals' backs and mounted into dorsal skinfold chambers. On days 1, 3, 5, 7 and 10 after surgery, nutritive tissue perfusion, angiogenesis and flap necrosis were evaluated using intravital fluorescence microscopy. Thereafter, the flap tissue was excised and fixed for histological and immunohistochemical analyses. The flaps of PF-treated animals exhibited a higher functional capillary density and more newly formed microvessels, resulting in a significantly increased flap survival rate. Moreover, they contained a lower number of myeloperoxidase (MPO)-positive neutrophilic granulocytes and cleaved caspase-3-positive apoptotic cells in the transition zone between vital and necrotic flap tissue. These findings indicate that short-term PF improves tissue survival in ischemically challenged musculocutaneous flaps by maintaining nutritive blood perfusion and dampening ischemia-induced inflammation.
周期性禁食（PF）作为一种饮食限制形式，已被证明能在几种不同组织中诱导针对缺血性损伤的组织保护作用。因此，在本研究中，我们分析了短期24小时禁食是否适合预防经历急性持续性缺血的肌皮瓣组织坏死。将C57BL/6N小鼠随机分为PF组（n = 8）和对照组，对照组可自由获取标准食物（n = 8）。PF组动物在皮瓣掀起前立即进行24小时禁食，并在10天观察期的其余时间可自由获取食物。在动物背部解剖随机模式设计的肌皮瓣，并将其植入背部皮褶小室。在术后第1、3、5、7和10天，使用活体荧光显微镜评估营养组织灌注、血管生成和皮瓣坏死情况。此后，切除皮瓣组织并固定以进行组织学和免疫组织化学分析。PF处理动物的皮瓣表现出更高的功能性毛细血管密度和更多新形成的微血管，导致皮瓣存活率显著提高。此外，在存活和坏死皮瓣组织之间的过渡区，它们所含的髓过氧化物酶（MPO）阳性中性粒细胞和裂解的半胱天冬酶-3阳性凋亡细胞数量较少。这些发现表明，短期PF通过维持营养性血液灌注和减轻缺血诱导的炎症来提高缺血性挑战的肌皮瓣中的组织存活率。
