NASA Logo

NTRS

NTRS - NASA Technical Reports Server

Back to Results
Animal models and their importance to human physiological responses in microgravityTwo prominent theories to explain the physiological effects of microgravity relate to the cascade of changes associated with the cephalic shifts of fluids and the absence of tissue deformation forces. One-g experiments for humans used bed rest and the head-down tilt (HDT) method, while animal experiments have been conducted using the tail-suspended, head-down, and hindlimbs non-weightbearing model. Because of the success of the HDT approach with rats to simulate the gravitational effects on the musculoskeletal system exhibited by humans, the same model has been used to study the effects of gravity on the cardiopulmonary systems of humans and other vertebrates. Results to date indicate the model is effective in producing comparable changes associated with blood volume, erythropoiesis, cardiac mass, baroreceptor responsiveness, carbohydrate metabolism, post-flight VO2max, and post-flight cardiac output during exercise. Inherent with these results is the potential of the model to be useful in investigating responsible mechanisms. The suspension model has promise in understanding the capillary blood PO2 changes in space as well as the arterial PO2 changes in subjects participating in a HDT experiment. However, whether the model can provide insights on the up-or-down regulation of adrenoreceptors remains to be determined, and many investigators believe the HDT approach should not be followed to study gravitational influences on pulmonary function in either humans or animals. It was concluded that the tail-suspended animal model had sufficient merit to study in-flight and post-flight human physiological responses and mechanisms.
Document ID
20040173132
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
Authors
Tipton, C. M.
(University of Arizona Tucson 85721-0093, United States)
Date Acquired
August 22, 2013
Publication Date
October 1, 1996
Publication Information
Publication: Medicine and science in sports and exercise
Volume: 28
Issue: 10 Suppl
ISSN: 0195-9131
Subject Category
Aerospace Medicine
Distribution Limits
Public
Copyright
Other
Keywords
NASA Discipline Cardiopulmonary
Non-NASA Center
NASA Program Flight
Flight Experiment
NASA Discipline Number 00-00
short duration
manned
STS-40 Shuttle Project
NASA Discipline Number 14-10
NASA Program Space Physiology and Countermeasures

Available Downloads

There are no available downloads for this record.
No Preview Available