The HPA system is a key hormonal component of the brain-gut axis

抄録

Bi-directional communication between the brain and the gut plays critically important role in health and disease. The first brilliant demonstration of the brain-gut communication was the cephalic phase of gastric and pancreatic secretion, discovered in Russia by Ivan Pavlov. The communication occurs through neuronal pathways including the vagus nerve, hormonal pathway as well as components of the immune system and the gut microbiota. In the presentation we will provide data on the main hormonal component of brain-gut axis, namely the hypothalamic-pituitary-adrenocortical (HPA) system and emphasize its gastroprotective role. The results of our studies suggest that the activation of the HPA system is gastroprotective component of stress response and glucocorticoids released in response to stress are gastroprotective but not ulcerogenic factors as previously accepted for several decades. Contribution of glucocorticoids to protective influence of preconditioning mild stress on the gastric mucosa is further confirmation of physiological gastroprotective role stress-produced glucocorticoids. The fact that the disturbance of the normal stress reaction by the elimination of the HPA axis's functioning leads to negative effects on the body such as the development and aggravation of gastric ulcer disease proves that stress-induced activation of the HPA axis plays a leading role in maintaining the physical health of the body. Gastroprotective effects of glucocorticoids may be mediated by multiple actions, including maintenance of gastric mucosal blood flow, mucus production, and attenuation of enhanced gastric motility and microvascular permeability. Glucocorticoids may contribute to gastroprotection by maintaining general body homeostasis, including glucose levels and systemic blood pressure, which could be a basis for their beneficial influence on the gastric mucosal integrity. Glucocorticoids exert gastroprotective actions in co-operation with prostaglandins, nitric oxide and capsaicin-sensitive sensory neurons. The findings provide novel insight for understanding of the potential role of the HPA system as important hormonal branch of the brain-gut communication. According to the findings activation of the HPA system is gastroprotective component of the brain-gut axis. This study was supported by Russian Science Foundation (RSF) N 14-15-00790.