Institute of Veterinary Anatomy, Histology and Embryology, Faculty of Veterinary Medicine, Leipzig University, Germany.
Fachdienst Gesundheit, Altenburg, Germany.
PLoS One. 2021 May 20;16(5):e0251530. doi: 10.1371/journal.pone.0251530. eCollection 2021.
Distal axonopathy is seen in a broad range of species including equine patients. In horses, this degenerative disorder of the recurrent laryngeal nerve is described as recurrent laryngeal neuropathy (RLN). The dysfunctional innervation of the cricoarytenoideus dorsalis muscle (CAD) leads to a loss of performance in affected horses. In general, ex vivo models of the larynx are rare and for equine patients, just one short report is available. To allow for testing new therapy approaches in an isolated organ model, we examined equine larynges in a constant pressure perfused setup. In order to check the vitality and functionality of the isolated larynx, the vessels´ reaction to norepinephrine (NE) and sodium nitroprusside (NP) as vasoactive agents was tested. Additionally, the contractility of the CAD was checked via electrical stimulation. To determine the extent of hypoxic alterations, lactate dehydrogenase (LDH) and lactate were measured and an immunofluorescent analysis of hypoxia-inducible factor (HIF-1α), a key transcription factor in hypoxia, was performed. For this, a hypoxia-induced cell culture for HIF-1α was developed. The application of NE led to an expected vasoconstriction while NP caused the expected vasodilation. During a perfusion period of 352 ±20.78 min, LDH values were in the reference range and lactate values slightly exceeded the reference range at the end of the perfusion. HIF-1α nuclear translocation could reliably be detected in the hypoxia-induced cell cultures, but not in sections of the perfused CAD. With the approach presented here, a solid basis for perfusing equine larynges was established and may serve as a tool for further investigations of equine larynx disorders as well as a transferrable model for other species.
远端轴索病可见于包括马属动物在内的广泛物种。在马中，这种复发性喉返神经退行性疾病被描述为复发性喉返神经病（RLN）。环杓后肌（CAD）的功能障碍神经支配导致受影响的马匹表现丧失。一般来说，喉的离体模型很少见，而对于马属动物，仅有一份简短的报告。为了在离体器官模型中测试新的治疗方法，我们在恒压灌注装置中检查了马的喉。为了检查离体喉的活力和功能，测试了血管对去甲肾上腺素（NE）和硝普钠（NP）作为血管活性物质的反应。此外，通过电刺激检查了 CAD 的收缩性。为了确定缺氧改变的程度，测量了乳酸脱氢酶（LDH）和乳酸，并且对缺氧诱导因子（HIF-1α）进行了免疫荧光分析，HIF-1α是缺氧中的关键转录因子。为此，开发了用于 HIF-1α的缺氧诱导细胞培养。NE 的应用导致预期的血管收缩，而 NP 导致预期的血管舒张。在 352 ±20.78 分钟的灌注期间，LDH 值在参考范围内，并且在灌注结束时乳酸值略高于参考范围。在缺氧诱导的细胞培养中可以可靠地检测到 HIF-1α核易位，但在灌注的 CAD 切片中则不能。通过本文提出的方法，为灌注马的喉建立了坚实的基础，可作为进一步研究马喉疾病的工具，以及其他物种的可转移模型。
