Peripheral and central pathophysiological changes in a new rat model of acid reflux combined with mental stress

Background Mental stress is an important risk factor for gastroesophageal reflux disease (GERD), which interacts with acid reflux and affects the efficacy of single acid suppression treatment. However, the specific mechanism remains elusive, and there is a lack of available models for further support. Methods This study established a new compound model combining acid reflux and chronic unpredictable mild stress (CUMS) to observe potential peripheral and central pathophysiological changes. Key Results Rats in the compound model suffered from significant weight loss and manifested depression-like behaviours. In addition, the acid reflux was not aggravated despite the presence of mental stress, along with dilated intercellular space (DIS), increased expression of desmoglein-1 (DSG1) mRNA, and injury of the lower oesophageal mucosa. The balance between pro-inflammatory and anti-inflammatory factors was disrupted. In the hypothalamus of rats in the compound model, the expression of corticosterone-releasing factor (CRF) and its receptors, protein kinase A (PKA), and gamma-aminobutyric acid (GABA) receptors were decreased. This might be related to the "escape" of stress, which weakened the suppressive effect on excitatory transmission to cope with the damage of pressure to the body. Conclusions & Inferences Mental stress and acid reflux affect GERD through peripheral and central aspects, which can result in the poor efficacy of acid inhibitors. This may provide a new direction for the treatment of GERD.