Cox Abigail, Cannes do Nascimento Naila, Pires Dos Santos Andrea, Sivasankar M Preeti
Department of Comparative Pathobiology, Purdue University, West Lafayette, Indiana.
Department of Comparative Pathobiology, Purdue University, West Lafayette, Indiana.
J Voice. 2021 Jan;35(1):77-84. doi: 10.1016/j.jvoice.2019.06.009. Epub 2019 Jul 13.
This novel study sought to untangle the association between hydration state and the estrous cycle in the vocal folds, since the voice is reported to negatively change in speakers during the estrous cycle and with dehydration. We hypothesized that there would be alterations in vocal fold tissue morphology depending on hydration state and that these changes would vary with the estrous cycle.
Prospective, in vivo study design.
Female Sprague Dawley rats (n = 30) were used in this study. Sixteen rats were systemically dehydrated to an average of 10% reduction in body weight by withholding water (range of body weight loss: 8%-13%). Fourteen rats were assigned to euhydrated, control condition. Estrous stage of female Sprague Dawley rats (n = 30) was determined via cytological evaluation of vaginal smears. Following euthanization, larynges were prepared for histological staining with hematoxylin and eosin, Masson's trichrome and alcian blue (pH 2.5). To quantify hyaluronan, alcian blue staining was completed pre- and posthyaluronidase incubation. The change in staining percent was quantified with image analysis algorithms and reported as the hyaluronan quantity. Relative collagen distribution (index of dehydration), hyaluronan quantity, and tissue morphology were the outcome measures.
Systemic dehydration was associated with changes in hyaluronan quantity in the rat vocal fold lamina propria. Dehydration did not significantly affect the collagen distribution nor the tissue morphology. Estrous stage alone does not impact the quantity of vocal fold hyaluronan, alter tissue morphology, or change collagen distribution.
Decreases in hyaluronan quantity in the lamina propria of the rat vocal fold may play a role in tissue fluid balance during systemic dehydration. Future studies will expand this work to investigate additional components of the vocal fold extracellular matrix to fully elucidate the impact of hydration state on the vocal fold.
这项新研究旨在理清水合状态与声带发情周期之间的关联，因为据报道，在发情周期以及脱水过程中，说话者的声音会出现负面变化。我们假设，声带组织形态会根据水合状态发生改变，且这些变化会随发情周期而变化。
前瞻性体内研究设计。
本研究使用了30只雌性斯普拉格-道利大鼠。通过禁水使16只大鼠全身脱水，平均体重减轻10%（体重减轻范围：8%-13%）。14只大鼠被分配到正常水合的对照条件。通过阴道涂片的细胞学评估确定雌性斯普拉格-道利大鼠（n = 30）的发情阶段。安乐死后，准备喉部进行苏木精和伊红、马松三色染色以及阿尔辛蓝（pH 2.5）组织学染色。为了定量透明质酸，在透明质酸酶孵育前后完成阿尔辛蓝染色。用图像分析算法对染色百分比的变化进行定量，并报告为透明质酸量。相对胶原分布（脱水指数）、透明质酸量和组织形态为观察指标。
全身脱水与大鼠声带固有层透明质酸量的变化有关。脱水对胶原分布和组织形态没有显著影响。仅发情阶段不会影响声带透明质酸量、改变组织形态或改变胶原分布。
大鼠声带固有层透明质酸量的减少可能在全身脱水期间的组织液平衡中起作用。未来的研究将扩展这项工作，以研究声带细胞外基质的其他成分，从而全面阐明水合状态对声带的影响。
