Role of the apelin on the hypothalamic-pituitary-adrenal axis of rats submitted to water privacy

• Grant number: 17/20923-7
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Effective date (Start): April 01, 2018
• Effective date (End): March 31, 2019
• Field of knowledge: Biological Sciences - Physiology - Physiology of Organs and Systems
• Principal Investigator: José Antunes Rodrigues
• Grantee: Fernanda Santos de Oliveira
• Host Institution: Faculdade de Medicina de Ribeirão Preto (FMRP). Universidade de São Paulo (USP). Ribeirão Preto , SP, Brazil

Abstract

It is known that apelin has a function in several tissues of the human body, and that both its APJ receptor and the peptide itself and their respective mRNAs have been found inthe central nervous system (CNS) by different techniques. Recent studies have demonstrated that, more than that, the apelinergic system is found in the paraventricular (PVN) and supraoptic nucleus (NSO) of the hypothalamus, sites that have an important role in thehydroelectrolytic balance, because they contain osmoreceptors and vasopressinergic neurons. Changes in the hydroelectrolytic balance, caused by a water deprivation, inducephysiological responses of hormonal and behavioral secretion, these physiological responses are critical to the maintenance of the balance allowing an adaptation of the system, reestablishing the homeostasis. The hyperosmotic stress (water deprivation) leads to thesecretion of AVP (vasopressin), which promotes an increase in the renal reabsorption of 3Proposta ICwater, causing a reduction in the excretion of water, which together with the ingestionstimulated by the osmoreceptors related to thirst behavior, allow the osmolality of theextracellular fluid returns to equilibrium.An important endocrine response to stressful events is the activation of the hypothalamic-pituitary-adrenal (HPA) axis, when activated corticotrophin releasing hormone(CRH) secretion is activated, stimulating the adrenocorticotrophic hormone (ACTH) release by adenohypophysis and consequently leads the adrenal gland to produce mainly glucocorticoids. The main nucleus that integrates the neuroendocrine adjustments to the stressis the PVN, that has proven the present apelinérgico system, then during a water deprivation the apelin could have some influence in the activation or deactivation of the axis. Thus the present work aims to study the role of apelin on the HHA axis, during a hyperosmotic stress, both in the hydromineral intake and in the secretion of hormones acting on the axis. (AU)