Guyton J R, Lindsay K L, Dao D T
Am J Pathol. 1983 May;111(2):234-46.
Age-related ultrastructural changes in the intima and inner media of rat thoracic aorta were examined by new morphometric techniques. Young adult male rats, 10 weeks old, were compared with 1-year-old male rats. The most marked changes were found in the sub-endothelium, which increased in thickness more than five-fold. Basement-membrane-like and granular material accounted for the bulk of this thickening. Certain other structures were increased sevenfold or more in subendothelium. These structures and the volume fractions they occupied in 1-year-old rats were as follows: banded collagen, 4.3%; mononuclear leukocytes, 4.5%; cystic structures, 3.3%; and fibrillar elastin, 1.0%. Changes were also demonstrated in the fenestrae of and at selected depth levels below the innermost, or alternatively the internal, elastic lamina. Collagen increased strikingly within fenestrae and just below the elastic lamina. This was associated with a 28% increase in the thickness of the elastic lamina and a recession of smooth muscle cytoplasm to a deeper position within the first musculoelastic medial layer. The alterations in subendothelial tissues imply an altered basis for mechanical support for aortic endothelium in aging rats. These results mark the successful application of micro-computer-based stereology to a situation of polarized geometry.
采用新的形态计量学技术，研究了大鼠胸主动脉内膜和中膜内层与年龄相关的超微结构变化。将10周龄的成年雄性幼鼠与1岁雄性大鼠进行比较。最显著的变化出现在内皮下层，其厚度增加了五倍多。基底膜样物质和颗粒状物质占了这种增厚的大部分。内皮下层的某些其他结构增加了七倍或更多。这些结构及其在1岁大鼠中所占的体积分数如下：带状胶原，4.3%；单核白细胞，4.5%；囊性结构，3.3%；以及纤维状弹性蛋白，1.0%。在最内层或内弹性膜下方选定深度水平处的窗孔中也显示出变化。窗孔内和弹性膜下方的胶原显著增加。这与弹性膜厚度增加28%以及平滑肌细胞质向第一个肌弹性中层内更深位置退缩有关。内皮下组织的改变意味着老年大鼠主动脉内皮机械支持的基础发生了改变。这些结果标志着基于微型计算机的体视学在极化几何情况下的成功应用。
