実験的サル冠動脈硬化性病変の病理学的検討

Abstract

Pathological analysis with ultrastructural study was employed to observe and to compare in detail lesions of the coronary artery of cynomolgus and rhesus monkeys. Animals were fed individually with the same atherogenic ration under identical conditions for 4, 8, and 12 months, and controls of each species were fed with a low fat, cholesterolfree ration. Transmission electron microscopic studies of coronary arteries from these animals showed the following conclusions.1) Synthetic smooth muscle cells (SMC) without lipid and macrophages without lipid appeared more frequently in the cynomolgus lesions than in the rhesus. Furthermore, phenotypic expression of synthetic SMCs in the cynomolgus was more active with greater diversity, while the rhesus showed less phenotypic modulation. 2) Increased percentage of both synthetic SMCs with lipid and macrophages with lipid were demonstrated in the cynomolgus lesions as compared to those of the rhesus. This indicated that foam cells including SMC and macrophage-derived foam cells, are more prevalent in cynomolgus than in rhesus. 3) Medial disruption, synthetic SMCs and macrophages containing lipid appeared more often in cynomolgus media than in rhesus media. 4) There were greater percentages on the myocardial side of both synthetic SMCs and macrophages in the intima of both species. 5) Approximately 42% of all foam cells in the cynomolgus intimal lesion was derived from SMC. There were fewer macrophages in rhesus lesions. 6) The difference in expression between the two macaque species was dependent on different responses of macrophages as reticuloendothelial system and of SMCs as medial components. The configuration of the artery wall could be one of the important atherogenic factors.