1979 Volume 6 Issue 4 Pages 559-565
It was previously reported that there was the decrease in linolate ratio and increase in oleate ratio of cholesteryl ester (CE) of serum lipoproteins (LPs) in atherosclerotic disease.
To clarify the significance of these changes in fatty-acid-compositions (FAC) in atherosclerosis, an attempt was made in this paper to investigate the changes in FAC of CE of serum LPs, liver and aortic wall in the process of development and regression of experimental atherosclerosis, which was induced with 0.5% cholesterol diet in female albino rabbits weighting around 2.5kg.
Atheromatous lesions were remarkably pronounced 10 weeks after the initiation of this experiment. Experimental animals were divided into 6 groups and all of them were sacrificed at the end of the experiment.
Part I; observation of the process of development of atherosclerosis.
Subgroup A: fed a normal diet for 20 weeks.
Subgroup B: fed a cholesterol diet for 24 weeks. Part II; observation of the process of regression for 8 weeks.
All of the subgroups C, D, E and F were fed a cholesterol diet for 12 weeks, and subgroup C was sacrificed at 12 weeks.
After this 12 weeks, subgroup D fed a cholesterol-free diet up to 20 weeks, subgroup E fed a cholesterol-free diet with 200mg of PPC a day up to 20 weeks, subgroup F fed a cholesterol-free diet with 200mg of BCPMP a day up to 20 weeks.
1) In subgroup B, the FAC of CE of serum LPs (VLDL, LDL) gradually increased in oleate ratio and gradually decreased in linolate ratio from 4 weeks.
2) The changes of FAC of CE in liver and aortic wall were similar to those of serum LPs in subgroup B.
3) Both subgroups B and C showed the similar change in FAC of serum LP, liver and aortic wall. In both subgroups D and E were recognized the increase of linolate ratio and the decrease of oleate ratio in serum LPs at 20 weeks. The changes of subgroup F in FAC of serum LPs were similar to those of subgroup C. The changes of subgroup D, E and F in FAC of aortic wall were similar to those of subgroup B.
4) The proportion of atheromatous lesions in thoracic and abdominal aorta were ranged from 30 to 60% in subgroup D, E and F. This might imply that there were no significant differences in three subgroups.
5) On histological findings, the intimal foam cells were markedly noted, but the intimal smooth-muscle cells were less remarkable in subgroup D. While, in subgroup E the intimal smooth-muscle cells were markedly ovserved, but the intimal foam cells were less prominent. Both the intimal smooth-muscle cells and foam cells were moderately observed in subgroup F.
6) Consequently, these results lead us to believe that the continuous increase in oleate ratio and decrease in linolate ratio in CE of serum LPs were one of the pathogenic factors and the potent factors of development in experimental atherosclerosis in rabbits.
We also observed the decrease in oleate ratio and increase in linolate ratio of CE of serum LPs and liver, in subgroups D and E, these changes would be indicative of regression in atherosclerosis.
