Accession Number:

ADA159363

Title:

Simultaneous Determination of Fluid Shifts during Thermal Stress in a Small Animal Model,

Descriptive Note:

Corporate Author:

ARMY RESEARCH INST OF ENVIRONMENTAL MEDICINE NATICK MA

Report Date:

1985-09-01

Pagination or Media Count:

21.0

Abstract:

We have developed methodology to measure simultaneously fluid redistribution among the major compartments during moderate and severe hypohydration. Total body water TBW was determined using tritiated water, extracellular fluid volume, ECF was measured using a single injection C-14 inulin technique, and plasma volume PV was determined by cardio-green dye dilution. Moderate 10 decrease in body weight and severe 15 hypohydration resulted in significant losses in TBW, ECF and PV. Plasma volume was decreased by approximately 25 in both groups, and other fluid compartments were differentially affected. For example, the moderately dehydrated group maintained PV by shifting fluid from the ECF and ISF interstitial fluid compartment while preserving the ICF intracellular fluid conversely, the severely dehydrated group maintained PV by redistributing fluid from both the ECF and ICF compartments. The data indicated that the initial response to fluid loss was the movement of fluid from the ECF pool to sustain both PV and ICF. In severely hypohydrated rats, PV was maintained at the expense of ICF. These experiments indicated that PV and ICF were maximally protected, probably to preserve the integrity of the cardiovascular system and to minimize organ injury.

Subject Categories:

  • Stress Physiology

Distribution Statement:

APPROVED FOR PUBLIC RELEASE