Fonseca Jorge, Martins-dos-Santos José, Oliveira Pedro, Laranjeira Nuno, Aguas Artur, Castelo-Branco Nuno
Instituto Superior de Ciências da Saúde Egas Moniz, Almada, Portugal.
Arq Gastroenterol. 2012 Jan-Mar;49(1):82-8. doi: 10.1590/s0004-28032012000100014.
Only a few studies evaluated the digestive alterations caused by low frequency noise (LFN) and most focused only on mucosal alterations.
To investigate the morphological injury of LFN-exposed gastric wall, beyond the epithelial layer.
Wistar rats were exposed to low frequency noise (LFN), during increasing periods, 1 to 13 weeks. A control group was kept in silence. Gastric specimens were studied using: (i) light microscopy with hematoxylin-eosin and immunostaining for collagens; (ii) transmission electron microscopy; (iii) morphometry allowing statistical analysis.
Submucosa of all LFN-exposed animals exhibit increased thickness with fibrous proliferation. Transmission electron microscopy showed massive collagen deposition. Immunostaining identified collagen IV as responsible for the increased thickness. Morphometry allowed the demonstration of a significant difference of thickness between control and exposed groups. Vascular alterations included: i) intima proliferation and thickening, rupture of the internal elastic lamina, thrombotic changes; ii) thickening of the media; iii) after 9 weeks of LFN-exposure, we found new formed vessel presenting tortuous and twisted. There is a significant difference of arterial wall thickness between control and exposed groups.
Deeper layers of gastric wall undergo alterations, including fibrosis of the submucosa caused by collagen IV deposition, an early marker of neoangiogenesis. Vascular alterations included thickening and thrombotic phenomena, but also images of newly formed vessels. This study suggests that, at least in the stomach, LFN-induced fibrosis could be linked with neoangiogenesis.
仅有少数研究评估了低频噪声（LFN）引起的消化改变，且大多数研究仅关注黏膜改变。
研究暴露于低频噪声的胃壁除上皮层之外的形态学损伤。
将Wistar大鼠在1至13周的时间内逐渐暴露于低频噪声中。设立一个安静环境下的对照组。使用以下方法研究胃标本：（i）苏木精-伊红染色及胶原免疫染色的光学显微镜检查；（ii）透射电子显微镜检查；（iii）形态测量学以便进行统计分析。
所有暴露于低频噪声的动物的黏膜下层均表现出厚度增加及纤维组织增生。透射电子显微镜检查显示大量胶原沉积。免疫染色确定Ⅳ型胶原是厚度增加的原因。形态测量学证实对照组和暴露组之间厚度存在显著差异。血管改变包括：i）内膜增生和增厚、内弹性膜破裂、血栓形成改变；ii）中膜增厚；iii）在暴露于低频噪声9周后，发现新形成的血管呈现扭曲状。对照组和暴露组之间动脉壁厚度存在显著差异。
胃壁深层发生改变，包括由Ⅳ型胶原沉积引起的黏膜下层纤维化，这是新生血管形成的早期标志物。血管改变包括增厚和血栓形成现象，以及新形成血管的影像。本研究表明，至少在胃中，低频噪声诱导的纤维化可能与新生血管形成有关。
