SERUM-LIPOPROTEIN LEVELS IN GENETICALLY HYPERCHOLESTEROLEMIC RICO RATS - EFFECTS OF A HIGH-SUCROSE-CHOLESTEROL DIET WITHOUT OR WITH ALTEREDMAGNESIUM AND FLUORIDE CONTENT

Genetically hypercholesterolaemic RICO rats (male, 6 weeks old) were r andomly distributed into 6 experimental groups. The zero-time basal gr oup A was sacrificed at the start of the experiment while the other gr oups were fed for 6 weeks and then sacrificed. Group B was fed a stock diet. Control group C was fed a high-sucrose (45%) diet with 0.5% add ed cholesterol. In the diet of group D, only the magnesium (Mg) conten t was reduced from the level of group C (883 ppm) to 200 ppm. The diet of group E was the same as that of group D with the addition of 12 pp m of fluoride (F) and the diet of group G was the same as that of grou p E, but with its Mg content elevated from 200 ppm to 300 ppm. Analysi s of aortic blood samples, taken before sacrifice, indicated significa nt increases in total serum cholesterol (p<0.01), very low density lip oprotein (VLDL) (p<0.001) and low density lipoprotein (LDL), (p<0.001) cholesterol, and a trend to lower high density lipoprotein (HDL) chol esterol in group C, as compared to group B. Significantly lower total (p<0.05), VLDL (p<0.01) and LDL (p<0.01) triglycerides were observed i n group C when compared to group B. The LDL phospholipids were signifi cantly higher in group C (p<0.001) than in group B. When cholesterol l evels in groups D, E and G were compared with group C,the VLDL cholest erol in group E and the LDL cholesterol in group G were slightly but s ignificantly (p < 0.05) reduced, while total cholesterol and the other subfractions were unaltered. The LDL triglycerides of groups E and G were significantly smaller still than the already small fraction in gr oup C. The VLDL triglyceride in group E was significantly lower than t hat of group C (35% reduction, p<0.001), D and G (p<0.05). Phospholipi ds were slightly but significantly reduced in the VLDL fraction of gro up E and in the LDL fraction of group G (p<0.05 and 0.01, respectively ), as compared to those of group C.