[Relationship between the concentration of vitamin A in the liver of the lesser suslik, Citellus pygmaeus, and the altitude of its habitat].

With the increase of the altitude of habitation of the ground-squirrel C. pygmaeus the content of vitamin A in its liver decreases. It is suggested that low vitamin A content of the liver in mountain animals is due to the increased utilization of vitamin A and carotenoids which provides for adaptation of these animals to lower partial oxygen pressure and lower temperature.