Background: The brain and the gut interact bi-directionally through
the brain-gut axis. The interaction is mediated by the autonomic nervous system
and the hypothalamic-pituitary-adrenocortical (HPA) system. The first brilliant
demonstration of the brain-gut interactions was the cephalic phase of gastric and
pancreatic secretion discovered by Ivan Pavlov, the first physiologist who was
awarded the Nobel Prize for Physiology or Medicine in 1904. This review aims to
identify the HPA system as a key hormonal branch of the brain-gut axis in stress.
Methods: We first outlined main components of the brain-gut axis and then focused
on the HPA system as a key hormonal branch of the brain-gut axis in stress. We
undertook a structured search of bibliographic databases for peer-reviewed research
literature using a focused review question.
Results: Seventy-one articles were included in the review, the eleventh of them were articles of Filaretova
L. and co-authors. We will discuss in our articles how an endocrinological approach to
gastroenterological field can advance our understanding of the HPA axis role in regulation of gastric
mucosal integrity and uncover new findings. According to these findings activation of the HPA system is
gastroprotective component of the brain-gut axis in stress but not ulcerogenic one as it was generally
accepted. Corticotropin-releasing factor (CRF) and glucocorticoids are important natural players provided
gastroprotection. The results suggest that an initial action of endogenous glucocorticoids, including
stress- and CRF-produced ones, as well as exogenous glucocorticoids, even used at pharmacological
doses, is physiological gastroprotective. Prolongation of the hormonal action may lead to the
transformation of gastroprotective hormonal effect to proulcerogenic one.
Conclusion: The findings of this review demonstrate that corticotropin-releasing factor and
glucocorticoids contribute to the realization of the brain-gut interactions and that activation of the HPA
system is gastroprotective component of this interaction in stress.