Physiology Research Center, Kerman University of Medical Sciences, Kerman, Iran.
Iran J Basic Med Sci. 2013 Jun;16(6):790-6.
OBJECTIVE(S): Gastroesophageal Reflux Disease (GERD) is one of the most common digestive disorders that frequently lead to pulmonary complications due to gastric fluid aspiration. In the present experimental study, chronic aspiration of gastric fluid, its components and bile salts in rat lung was performed to find out the main factor(s) causing pulmonary complications of gastric fluid aspiration.
Forty eight male rats weighted 250-300 g were selected in six groups. After anesthesia and tracheal cannulation, the animals received 0.5 ml/kg normal saline, 0.5 ml/kg of whole gastric fluid, 0.5 ml/kg pepsin (2.5 µg/ml), 0.5 ml/kg hydrochloric acid (pH=1.5) or 0.5 ml/kg bile salts (2.5 µg/ml) by injection into their trachea and lungs. In sham group nothing was injected.
Parenchymal and airways inflammation and fibrosis of bronchi, bronchioles and parenchyma were significantly more in the test groups compared to saline and sham groups (P<0.001); also inflammation in pepsin and bile salts groups (histopathology scores: 2.87±0.35 and 3.0±0.0 for bronchial, 2.87±0.35 and 2.87±0.35 for bronchioles, 2.87±0.35 and 2.87±0.35 for parenchymal inflammation) were more than hydrochloric acid and gastric fluid groups (1.75±0.46 and 2.5±0.53 for bronchial, 2.0±0.0 and 2.0±0.0 for bronchioles, 2.0±0.0 and 2.0±0.0 for parenchymal inflammation) (P<0.05). The same results were found for fibrosis, so that the fibrosis in pepsin and bile salts groups were more than hydrochloric acid and gastric fluid groups (P<0.05). Conclusion : The present results suggested that pulmonary complications causing from bile salts and pepsin might be more than gastric juice and hydrochloric acid.
胃食管反流病（GERD）是最常见的消化系统疾病之一，由于胃内容物吸入，常导致肺部并发症。在本实验研究中，通过向大鼠肺部慢性吸入胃液、其成分和胆盐，以找出导致胃液吸入性肺部并发症的主要因素。
选择 48 只体重 250-300 克的雄性大鼠，分为 6 组。麻醉和气管插管后，动物通过气管内注射 0.5ml/kg 生理盐水、0.5ml/kg 全胃液、0.5ml/kg 胃蛋白酶（2.5μg/ml）、0.5ml/kg 盐酸（pH=1.5）或 0.5ml/kg 胆盐（2.5μg/ml）。假手术组不注射任何物质。
与生理盐水和假手术组相比，试验组的实质和气道炎症以及支气管、细支气管和实质的纤维化明显更严重（P<0.001）；胃蛋白酶和胆盐组的炎症（组织病理学评分：支气管为 2.87±0.35 和 3.0±0.0，细支气管为 2.87±0.35 和 2.87±0.35，实质炎症为 2.87±0.35 和 2.87±0.35）也高于盐酸和胃液组（支气管为 1.75±0.46 和 2.5±0.53，细支气管为 2.0±0.0 和 2.0±0.0，实质炎症为 2.0±0.0 和 2.0±0.0）（P<0.05）。纤维化也有同样的结果，因此胃蛋白酶和胆盐组的纤维化比盐酸和胃液组更严重（P<0.05）。
本研究结果表明，由胆盐和胃蛋白酶引起的肺部并发症可能比胃液和盐酸更严重。
