Effect of a butter-rich diet on murine frostbite

A simple reproducible, humane model for producing frostbite in rodents is desirable. We have developed such a model and have investigated the effects of a butter-rich diet on severe cold injury. Mice (25 +/- 2 g) were randomly divided into two groups (n = 10). One group was given a standard rodent diet and the other group a butter-enriched (25%) rodent diet for 1 month. Under pentobarbital sodium anesthesia the mice were placed in a plastic funnel with the stem removed so that the entire tail protruded. The tails were submerged in a freezing solution (-18 degrees C) for 8 min. The mice received no further treatment. Tail lengths were measured 2 weeks after freezing to determine the amount of tail surviving from cold injury after autoamputation. Mean tail lengths (cm +/- SD) for the two groups were as follows: butter-rich diet, 4.3 +/- 1.8; standard diet, 7.3 +/- 2.0 (P less than 0.002). A high saturated-fat diet has a deleterious effect in murine frostbite. This simple model can be employed to test various modalities in the treatment of frostbite.