A comparative study on dyslipidaemia inducing diets in various rat strains.

In our experiments we compared the serum lipoprotein lipid composition of Fischer 344 (F344) and Long-Evans (LE) inbred rats as well as of their hybrid FLF(1) from both sexes after feeding them for 2, 4 and 8 weeks with different diets. The following diets were used: 1) standard diet marked as CRLT/N; 2) diet reach in butter marked as BR; 3) diet containing cholesterol, sodium cholate and methylthiouracil marked as CR; 4) diet marked as BRC, which is the Hartroft-Sós diet modified by our research group consisting of the diets BR and CR. The latter diet was the most effective, because within two weeks the level of serum total cholesterol, LDL-cholesterol, HDL-cholesterol and triglyceride in the F344 female rats increased 8, 30, 4 and 8 times, respectively. The male rats of the Long-Evans strain showed moderately increased values while the FLF(1) female hybrids derived from the hybridization of LE males and F344 females had values closer to those of the mother strain. Despite the fact that during this time the LDL/HDL ratio increased from 0.06 to 2.97 and the PON-1 activity decreased to one-third, a significant lipid deposition could not be shown in the wall of the abdominal aorta even two months later. Our experimental model is suitable for the chemoprevention of dyslipidaemia or rapid testing of molecules chosen for its treatment.