Hoover G A, Nicolosi R J, Camp R R, Hayes K C
Arteriosclerosis. 1982 May-Jun;2(3):252-65. doi: 10.1161/01.atv.2.3.252.
To document naturally occurring aortic intimal changes with age in squirrel and Cebus monkeys, the aortic lipid class composition, histology, and fine structure were quantitatively compared in the two species at birth and in old age. The aortic intima plus inner media in the young squirrel monkey contained more lipid, particularly in the phospholipid and cholesterol ester fractions than in young Cebus. The lipid class composition of the old Cebus monkey aorta resembled that of the young Cebus. In the old squirrel monkey aorta, cholesteryl ester, and to a lesser extent, free cholesterol were increased over young levels, while the phospholipid concentration tended to be lower. The aortic cholesteryl ester:phospholipid ratio increased with age in both species, but the old Cebus monkey aorta maintained the ratio below unity at 0.3, whereas the old squirrel monkey aorta ratio was 2.5. The abdominal aorta of the old squirrel monkey tended to have more lipid in each class than the thoracic segment. Morphologically, the old Cebus monkey aortic intima was similar to the young Cebus in terms of the intima:media ratio, intimal cellularity, and the distribution of intimal components determined by points in electron micrographs. In both age groups the Cebus monkey aorta was characterized by diffuse intimal thickening without lipid deposits. In contrast, that old squirrel monkey aorta had a much greater intima:media ratio, especially in the abdominal aorta, and a greater intimal cellularity than the young squirrel monkey. The distribution of intimal components in electron micrographs of the old squirrel monkey aorta shifted to a predominance of extracellular lipid, smooth muscle cells, and collagen. Deposits of small dense granules, presumably the products of cellular breakdown, were observed in aortic intimas and medias of both species in old age. Thus, differences between Cebus and squirrel monkey aortic intimas were evident at birth. By old age, the Cebus monkey aortic intima remodeled without accumulating lipid, whereas the squirrel monkey developed aortic intimal lesions resembling human atherosclerosis.
为记录松鼠猴和僧帽猴主动脉内膜随年龄的自然变化，对这两个物种出生时和老年时的主动脉脂质类别组成、组织学和精细结构进行了定量比较。幼年松鼠猴的主动脉内膜加内中膜所含脂质更多，尤其是磷脂和胆固醇酯部分，比幼年僧帽猴的多。老年僧帽猴主动脉的脂质类别组成与幼年僧帽猴相似。在老年松鼠猴主动脉中，胆固醇酯以及程度较轻的游离胆固醇比幼年时有所增加，而磷脂浓度则趋于降低。两个物种的主动脉胆固醇酯与磷脂的比率均随年龄增加，但老年僧帽猴主动脉的该比率维持在0.3，低于1，而老年松鼠猴主动脉的比率为2.5。老年松鼠猴的腹主动脉各脂质类别中的脂质往往比胸段更多。形态学上，老年僧帽猴主动脉内膜在内膜与中膜的比率、内膜细胞密度以及电子显微镜照片中通过点确定的内膜成分分布方面与幼年僧帽猴相似。在两个年龄组中，僧帽猴主动脉的特征都是内膜弥漫性增厚且无脂质沉积。相比之下，老年松鼠猴主动脉的内膜与中膜比率大得多，尤其是在腹主动脉，且内膜细胞密度比幼年松鼠猴大。老年松鼠猴主动脉电子显微镜照片中的内膜成分分布转向细胞外脂质、平滑肌细胞和胶原蛋白占主导。在老年时，两个物种的主动脉内膜和中膜中均观察到小致密颗粒沉积，推测是细胞分解产物。因此，僧帽猴和松鼠猴主动脉内膜在出生时就存在差异。到老年时，僧帽猴主动脉内膜重塑且无脂质积聚，而松鼠猴则出现了类似人类动脉粥样硬化的主动脉内膜病变。
