[Change of pulmonary circulation in microgravity and simulated microgravity]

Area of Science:

• Physiology
• Space Medicine
• Cardiovascular Research

Background:

• Fluid shifts towards the head occur in microgravity and simulated microgravity.
• The pulmonary circulation is significantly affected by these fluid shifts.
• Increased and unevenly distributed blood and fluid content in the lungs is observed.

Purpose of the Study:

• To investigate the changes in the regulative function of pulmonary circulation during microgravity.
• To understand the mechanisms underlying pulmonary circulation alterations in microgravity by observing pulmonary vessel reactivity.

Main Methods:

• Utilizing animal models of simulated microgravity.
• Observing changes in pulmonary circulation and blood/fluid distribution in the lungs.
• Assessing the reactivity of pulmonary blood vessels.

Main Results:

• Fluid transfer cephalad leads to increased pulmonary blood and fluid volume.
• Uneven distribution of fluid within lung zones was noted.
• Capillary changes were observed in simulated microgravity models.

Conclusions:

• Pulmonary circulation is an early target of microgravity-induced fluid shifts.
• Further research into pulmonary vessel reactivity is needed to elucidate microgravity's effects on lung circulation.