The Effect of Ingested Fat on the Sterol Metabolism of Th.e White Rat*

This is a report of an investigation on the influence of ingested fats on the sterol metabolism of the white rat. No summation of the literature on sterol metabolism will be given, because the subject has been so recently reviewed by Bills (1). Only those contributions pertinent to this paper will be referred to. The procedure adopted was to place young litter mates on vegetable diets. This was done because it is now generally accepted that the plant sterols are either not absorbed at all or only to a slight degree. The rations, which are described in Table I, were supplemented with a vitamin B concentrate (Mead Johnson), carotene, and viosterol. Soy bean meal’ was chosen for the protein concentrate, because it contains considerable amounts of stigmasterol, a sterol which, according to Butenandt, Westphal, and Cobler (2), can be transformed in vitro into a product having many of the properties of the hormone found in the corpus luteum. Table I shows that in one series of experiments the soy bean meal was supplemented with 4 times as much corn oil as in the other. In a second series of experiments soy bean oil was’substituted for the corn oil. A record of food intakes was kept, a collection of the feces made, and changes in body weights recorded. The animals were killed at the end of experimental periods which varied from 5 to 7 weeks. The sterol contents of the livers, remaining