Moderate exercise increases endotoxin concentration in hypoxia but not in normóxia

• Grant number: 17/02965-4
• Support Opportunities: Regular Research Grants - Publications - Scientific article
• Start date: April 01, 2017
• End date: September 30, 2017
• Field of knowledge: Health Sciences - Physical Education
• Principal Investigator: Ronaldo Vagner Thomatieli dos Santos
• Grantee: Ronaldo Vagner Thomatieli dos Santos
• Host Institution: Instituto de Saúde e Sociedade (ISS). Universidade Federal de São Paulo (UNIFESP). Campus Baixada Santista. Santos , SP, Brazil

Abstract

Hypoxia and high altitudes affect various organs, which impairs important physiological functions, such as adisruption of the intestinal barrier mediated by increased translocation of bacteria and increased circulating endotoxin levels. Physicalexercise can alter endotoxin concentration in normoxia. The aim of this study is to evaluate the effects of moderate exercise onendotoxin concentration in normobaric hypoxia. Nine healthy male volunteers exercised on a treadmill for 60 minutes at an intensity of 50% VO2peak in normoxic orhypoxic conditions (4200 m). Blood was collected at rest, immediately after exercise and 1 hour after exercise to evaluate serumendotoxin levels. Under hypoxic exercise conditions, SaO2% saturation was lower after exercise compared with resting levels (P<0.05) andreturned to the resting level during recovery in normoxia (P<0.05). Endotoxin concentration increased after exercise in hypoxia (P<0.05); it remained high 1hour after exercise in hypoxia compared with normoxia (P<0.05) and was higher after exercise and recovery compared with resting levels (P<0.05). HR was higher during exercise in relation basal in both conditions (P<0.05) and RPR increase after 60minutes in comparison to 20minutes in hypoxia (P<0.05). Moderate exercise performed in hypoxia equivalent to 4200 m increased endotoxin plasma concentration after exercise. One hour of rest in normoxic conditions was insufficient for the recovery of circulating endotoxins. (AU)