APOE and hydrops fetalis: ApoE-/- rats given the pure high-fat diet (HF) had significantly higher concentrations of lipids (p < 0.01–p < 0.0001) in the liver as well as in the tail (both at 2 and 4 weeks) and portal vein (at 5 weeks, i.e., upon completion of the trial) than the corresponding parts in conventional rats (C) given the same high-fat diet (Table 1).