Cardiovascular System Under Simulated Weightlessness: Head-Down Bed Rest vs. Dry Immersion.

ABSTRACT:

Background

The most applicable human models of weightlessness are -6° head-down bed rest (HDBR) and head-out dry immersion (DI). A detailed experimental comparison of cardiovascular responses in both models has not yet been carried out, in spite of numerous studies having been performed in each of the models separately.

Objectives

We compared changes in central hemodynamics, autonomic regulation, plasma volume, and water balance induced by -6° HDBR and DI.

Methods

Eleven subjects participated in a 21-day HDBR and 12 subjects in a 3-day DI. During exposure, measurements of the water balance, blood pressure, and heart rate were performed daily. Plasma volume evolution was assessed by the Dill-Costill method. In order to assess orthostatic tolerance time (OTT), central h

SUBMITTER: Amirova L 

PROVIDER: S-EPMC7248392 | biostudies-literature | 2020

REPOSITORIES: biostudies-literature