Department of Internal Medicine V - Pulmonology, Allergology, Respiratory Intensive Care Medicine, Saarland University Hospital, 66424, Homburg, Germany.
Institute for Clinical & Experimental Surgery, Faculty of Medicine, Saarland University, 66421, Homburg, Germany.
Sci Rep. 2019 Mar 26;9(1):5170. doi: 10.1038/s41598-019-41590-7.
Intravital microscopy of orthotopic lung tissue is technically demanding, especially for repeated investigations. Therefore, we have established a novel approach, which allows non-invasive repetitive in vivo microscopy of ectopic lung tissue in dorsal skinfold chambers. Syngeneic subpleural peripheral lung tissue and autologous endometrium (control) were transplanted onto the striated muscle within dorsal skinfold chambers of C57BL/6 mice. Grafts were analysed by intravital fluorescence microscopy over 14 days. Angiogenesis occurred in the grafts on day 3, as indicated by sinusoidal microvessels on the grafts' edges with very slow blood flow, perifocal oedema, and haemorrhage. By day 10, lung transplants were completely revascularized, exhibited a dense network of microvessels with irregular diameters, chaotic angioarchitecture, and high blood flow. Compared to lung tissue, endometrial grafts contained a structured, glomerulus-like vessel architecture with lower blood flow. Despite missing ventilation, hypoxic vasoconstriction of the lung tissue arterioles occurred. In contrast, endometrium tissue arterioles dilated during hypoxia and constricted in hyperoxia. This demonstrates that ectopic lung grafts keep their ability for organ-specific hypoxic vasoconstriction. These findings indicate that our approach is suitable for repetitive in vivo pulmonary microcirculation analyses. The high blood flow and hypoxia-induced vasoconstriction in lung grafts suggest a physiological intrinsic vasoregulation independent of the recipient tissue.
活体正交肺组织显微镜检查技术要求高，特别是对于重复研究。因此，我们建立了一种新方法，允许在背部皮肤囊室中非侵入性重复活体异位肺组织显微镜检查。同种异体胸膜下周围肺组织和自体子宫内膜（对照）被移植到 C57BL/6 小鼠背部皮肤囊室的横纹肌中。在 14 天内通过活体荧光显微镜分析移植物。第 3 天，在移植物边缘出现了具有非常缓慢血流的窦状微血管，周围水肿和出血，表明发生了血管生成。第 10 天，肺移植完全再血管化，表现为具有不规则直径、混乱的血管生成和高血流的密集微血管网络。与肺组织相比，子宫内膜移植物含有结构更规则的肾小球样血管结构，血流较低。尽管没有通气，肺组织小动脉仍出现缺氧性血管收缩。相比之下，子宫内膜组织小动脉在缺氧时扩张，在高氧时收缩。这表明异位肺移植物保持其器官特异性缺氧性血管收缩的能力。这些发现表明，我们的方法适用于重复的活体肺微循环分析。肺移植物中的高血流和缺氧诱导的血管收缩表明存在与受体组织无关的生理内在血管调节。
