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 degrees C, replacing the toxic monoacylglycerol with safflower oil and/or raising the environmental temperature to 34 degrees C did not reverse the ultimate fatality caused by palmitoyl glycerol ingestion. If hypothermia was between 28 and 32 degrees C, high mortality was not reversed by feeding the unsaturated fat or raising the environmental temperature to 34 degrees 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.