Evaluation of hypotalamic neuronal impairment in vasopressin secretion during sepsis

• Grant number: 13/03723-3
• Support Opportunities: Scholarships in Brazil - Master
• Start date: July 01, 2013
• End date: June 26, 2015
• Field of knowledge: Biological Sciences - Physiology - Physiology of Organs and Systems
• Principal Investigator: Maria José Alves da Rocha
• Grantee: Luís Henrique Angenendt da Costa
• Host Institution: Faculdade de Odontologia de Ribeirão Preto (FORP). Universidade de São Paulo (USP). Ribeirão Preto , SP, Brazil
• Associated scholarship(s): 14/14615-0 - Microglia and astrocyte activation in vasopressinergic nuclei in severe sepsis, BE.EP.MS

Abstract

Sepsis and its complications (severe sepsis and septic shock) are still the main cause of death in intensive care units worldwide. Clinical and experimental studies, including those from our laboratory, have shown that in the early phase of sepsis there is a high plasma concentration of arginine vasopressin (AVP). However, during the pathophysiological process, although there is persistent hypotension, which would be a strong stimulus for the hormone secretion, its plasma concentrations remain inadequately low. One hypothesis suggested for this relative deficiency of AVP is the excessive production of nitric oxide (NO) in the central nervous system, which act by inhibiting hormone secretion, and could cause neuronal apoptosis by oxidative stress. In fact, our working group observed during experimental sepsis increased interleukin-1² (IL-1²) in plasma and the expression of inducible nitric oxide synthase (iNOS) in AVP-producing hypothalamic nuclei, which would explain the production center NO (observed by increased nitrate in the cerebrospinal fluid) and desregulate mitochondrial bioenergetics, causing oxidative stress and activation of the intrinsic pathway of apoptosis. In some infectious situations magnocellular neurons exhibit great vulnerability associated with increased expression of major histocompatibility complex class I (MHC-I) and infiltration of cytotoxic T lymphocytes or CD8 + (LT-CD8 +). Considering the role of AVP in the vasopressor response, the elucidation of the mechanisms of hormone synthesis could contribute to the therapy during sepsis. Thus, given the inflammatory conditions present in sepsis, our hypothesis is that the relative deficiency of AVP in the late phase of this pathophysiology is due to the increased expression of MHC-I and activation pathways of programmed cell death dependent on LT-CD8 + in magnocellular cells of the hypothalamus.

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

ANGENENDT DA COSTA, LUIS HENRIQUE; DOS SANTOS JUNIOR, NILTON NASCIMENTO; ROCHA CATALAO, CARLOS HENRIQUE; SHARSHAR, TAREK; CHRETIEN, FABRICE; ALVES DA ROCHA, MARIA JOSE. Vasopressin Impairment During Sepsis Is Associated with Hypothalamic Intrinsic Apoptotic Pathway and Microglial Activation. Molecular Neurobiology, v. 54, n. 7, p. 5526-5533, SEP 2017. (13/03723-3, 12/22246-9)

Academic Publications

(References retrieved automatically from State of São Paulo Research Institutions)

COSTA, Luís Henrique Angenendt da. Evaluation of hypothalamic impairment in vasopressin secretion during sepsis. 2015. Master's Dissertation - Universidade de São Paulo (USP). Faculdade de Medicina de Ribeirão Preto (PCARP/BC) Ribeirão Preto.