Simulation of the fluid retention effects of a vasopressin analog using the Guyton model of circulation.
Fluid-loading (FL) consisting of water and salt tablets equivalent of 32 oz of isotonic saline is a countermeasure currently in use by NASA to improve the orthostatic tolerance of astronauts during Shuttle reentry.  However, the effectiveness of this countermeasure has been observed to decrease with the duration of space flight.  Possible ways to improve fluid retention and thus the effectiveness of FL include use of analogs of vasopressin such as lypressin (LVP).  This study used a computer simulation approach to analyze the potential benefits on fluid retention with LVP administered before FL.
Srinivasan
R S
RS
KRUG Life Sciences, Houston, TX 77058.
Simanonok
K E
KE
Fortney
S M
SM
Charles
J B
JB
D001810:Blood Volume / Q000187:drug effects* / Q000502:physiology; D003198:Computer Simulation; D005440:Fluid Therapy; D018475:Head-Down Tilt; D006801:Humans; D007024:Hypotension, Orthostatic / Q000503:physiopathology / Q000517:prevention & control*; D008236:Lypressin / Q000494:pharmacology* / Q000627:therapeutic use*; D008955:Models, Cardiovascular; D013026:Space Flight; D013997:Time Factors; D018544:Weightlessness Countermeasures
D008236:Lypressin