ROLE OF CHEMORECEPTORS AS MICROGRAVITY SENSORS- AN APPROACH FROM PRECLINICAL MODEL TO HUMAN PERFORMANCE AND SPACEFLIGHT
Abstract
Microgravity is characterized by people or objects appearing to be weightless. Astronauts can experience microgravity during space flight. Indeed, in microgravity, astronauts can float on a spacewalk in their spacecraft - or outside. During space flight, the thoracic blood volume is fluid shift-mediated and increased, associated with reduced ambient pressure to the arms and legs. Interestingly, chemoreceptors are sensitive to blood flow. Therefore, it is reasonable to propose that the microgravity environment is able to promote a reduction of gravity pressure over blood vessels, modifying the carotid body (CB) activity and secondarily affecting the baroreflex responses. Thus, considering that baroreceptors are mechanically sensitive receptors, and chemoreceptors are capable of sensing blood flow redistribution, it is reasonable to propose that during and after microgravity exposure exists a baroreflex desensitization-resetting, secondary to chemoreflex alteration, which could compromise human cardiorespiratory and muscular responses during and after a space flight. This possible physiological adjustment during microgravity exposure has yet to be explored. Thus, the global aim of the present proposal is to determine the contribution of peripheral chemoreceptors as microgravity sensors on cardiorespiratory autonomic control during and after a simulated space flight. To resolve this aim we will use rats to determine the effects of simulated microgravity (tail head-down tilt model) on resting cardiorespiratory and autonomic functions. In addition, we will use hypoxia-hyperoxia to determine the contribution of CB peripheral chemoreceptors on cardiac and autonomic adjustments promoted by microgravity environment. Along with this, we will use chemogenetic approaches to study the contribution of CB type I and II cells on autonomic and cardiorespiratory control at rest and during exercise in animals subjected to simulated microgravity. Finally, we will study the role of CB chemoreceptors on the exercise performance deterioration and muscle disfunction promoted by microgravity exposure. With this proposal we will resolve the contribution of peripheral chemoreceptors as microgravity sensors, which could open a new avenue in the research of space science and human space conquest.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Feb 06, 2025
- Source ID
- FA95502410248
Entities
People
- David Andrade Andrade
Organizations
- Air Force Office of Scientific Research
- United States Air Force