Quantification of intimal cell masses and atherosclerotic lesions in coronary arteries of control and hyperlipidemic swine.

In the current study of swine coronary arteries, we have attempted to quantify the coronary intimal cell masses (ICM) with regard to two aspects: (1) percentage of total arterial wall cells (intimal plus medial) that are in the intima, and (2) percentage of arterial wall area occupied by intima. We have studied 4 coronary sites: left main stem (LMS), proximal right (RCA), proximal left circumflex (LCX), and proximal left anterial descending (LAD). In mash-fed ('normal') swine we carried out the study at 3 ages: 2, 5 and 12 months. In addition, we have carried out a similar study in swine fed hyperlipidemic (HL) diets for 3 or approximately 10 months starting at 2 months of age. In the control swine we found approximately 6% of the arterial wall occupied by intima at 2 months of age with no significant increases by 12 months. There were no consistent significant differences among the 4 coronary artery sites with regard to percentage of wall occupied by intima. When the HL diet was fed, there were significant increases in the percentage of the arterial wall occupied by intima (now atherosclerotic lesion) by 3 months on diet and much larger increases by 10 months (up to 87% of wall occupied by intimal lesion) with extensive regions of lipid-rich, calcific, necrotic debris. After 3 months on HL diet the RCA lesions occupied significantly greater percentages of areas than the other 3 sites but this difference had disappeared by 10 months on the HL diet.