Metabolic changes in the animals subjected to space flight

Area of Science:

• Space biology and physiology
• Endocrinology
• Metabolic research

Background:

• Space flight significantly impacts physiological systems.
• Glucocorticoids play a key role in stress response and metabolism.
• Understanding metabolic adaptations to space is crucial for astronaut health.

Purpose of the Study:

• To investigate the effects of space flight on amino acid metabolism enzymes.
• To assess changes in lipolysis in adipose tissue.
• To measure plasma corticosterone levels in rats after space flight and simulated conditions.

Main Methods:

• Rats were subjected to actual space flight (F) and simulated space flight (SM).
• Measured activity of liver enzymes: tyrosine aminotransferase (TAT), tryptophan pyrrolase (TP), serine dehydratase (SD), alanine aminotransferase (ALT), and aspartate aminotransferase (AST).
• Assessed basal and norepinephrine-stimulated lipolysis in adipose tissue and plasma corticosterone levels.

Main Results:

• Space flight (18.5 days) led to increased plasma corticosterone and rapid/slowly activating liver enzyme activity.
• Lipolysis stimulation by norepinephrine was reduced in flight and simulated flight rats, persisting after a 6-day recovery.
• Immobilization stress elicited a higher corticosterone response in flight rats compared to controls.

Conclusions:

• Space flight induces both acute and chronic stress responses, elevating corticosterone and altering liver enzyme activity.
• Significant changes in the regulation of lipolytic processes in adipose tissue occur after space flight.
• These metabolic alterations persist post-flight, suggesting long-term impacts on fat metabolism regulation.