Toxicity of Palmitoyl Glycerol to Mice: Hypothermia and Reversal of the Toxicity

Adult and weanling mice kept at low ambient temperatures show an increased sensitivity to the toxicity of dietary rac-1(3)-palmitoyl glycerol. When fed the palmitoyl glycerol, mice less than 6 wk old show a pronounced hypothermia that is prevented by adding safflower oil to the diet. A more moderate degree of hypothermia is seen with older animals. Once body temperature fell below 28°C, replacing the toxic monoacylglycerol with safflower oil and/or raising the environmental temperature to 34°C did not reverse the ultimate fatality caused by palmitoyl glycerol ingestion. If hypothermia was between 28 and 32°C, high mortality was not reversed by feeding the unsaturated fat or raising the environmental temperature to 34°C. However, a combination of both treatments reduced the mortality. Irrespective of body temperature, the hypothermia was eliminated by the warm ambient temperature, but mortality was high. Thus, although hypothermia is a sign of the toxicity of rac-1(3)-palmitoyl glycerol, it is not the immediate cause of death.