Effects of Hypothermia on Rat Reticuloendothelial Blood Clearance and Particulate Uptake.

摘要

Casualties resulting from the French and German incursions into Russia during the winters of the 19th and 20th centuries, respectively exemplify cold weather as a strategic element of war. From Valley Forge to the Chosin Reservoir, the U.S. Army has been made aware of the influence of cold weather conditions on soldier health. In times of relative peace, cold weather injuries for troops under training or deployment exceeded 500 cases for the winter of 1999/2000. While respectively cases of frostbite, immersion foot and chilblains occur more frequently than hypothermia; this more lethal form of cold-related insult represents a soldier injury in need of remedy. However, as in the days of the American Revolution, the doctrine of increasing insulation or evacuation to warmer environments remains the primary approach to guard against hypothermic mortality. Perhaps understanding the influences of hypothermia on body systems supporting resistance to stress and trauma may reveal strategies to lessen the possibility of a lethal consequence following hypothermia. The contribution of the reticuloendothelial system (RES) to survival following traumatic stress is well documented. This is especially true for physiological insults involving vascular shock, to include that associated with heatstroke. This impact of the RES is mediated, in part by its clearance of vascular debris to support blood vessel patency. The present study examined the effect of rat whole body hypothermia and hypothermia with rewarming on RES blood clearance and PU by RES organs. Findings revealed hypothermia significantly decreased RES clearance as a result of reduced liver particulate uptake. Following active rewarming, this decrement in RES function remained. Further study is recommended to determine if modulations in RES clearance capacity alters the outcome of hypothermia. Such studies may establish RES fitness as an important concept to support reductions in cold-induced mortality.