Björnheden T, Bondjers G
Arteriosclerosis. 1987 May-Jun;7(3):238-47. doi: 10.1161/01.atv.7.3.238.
The inner parts of the arterial wall depend upon diffusion for nutrition and oxygenation. During the atherosclerotic process, increased intimal thickness leads to impaired diffusion, and at the same time the oxygen requirements increase. On this basis it has been suggested that the balance between the supply and demand of oxygen in the arterial wall may be important for the fate of the initiated lesion. In the first part of the present study, the oxygen consumption was measured during perfusion in aortic intima-media segments from cholesterol-fed rabbits. The results indicated that the oxygen consumption per DNA increased with increasing degree of atherosclerotic involvement up to a certain level. For more diseased aortas, however, the oxygen consumption decreased again. In the second part of the study, the oxygen consumption was measured in foam cell and smooth muscle cell fractions isolated from rabbit aortic intima-media. These measurements indicated that the oxygen consumption of isolated foam cells was three times higher than that of isolated smooth muscle cells. It is proposed in the study that the increased oxygen consumption of the less diseased aortas reflected an increased proportion of foam cells in the arterial wall. As the lesions grow and the number of foam cells in the intima increases, the available diffusion capacity for oxygen and nutrients to deeper parts of the lesion may become insufficient, leading to the observed decrease in cellular oxygen consumption of the more diseased samples. Hypoxic cell damage and further tissue reactions may occur and the healing of the initiated lesion may be endangered.
动脉壁的内部依靠扩散作用来获取营养和进行氧合作用。在动脉粥样硬化过程中，内膜厚度增加会导致扩散受损，同时氧需求增加。基于此，有人提出动脉壁内氧的供需平衡对于起始病变的转归可能很重要。在本研究的第一部分，对喂食胆固醇的兔子的主动脉内膜 - 中膜段进行灌注时测量了氧消耗。结果表明，每单位DNA的氧消耗随着动脉粥样硬化累及程度的增加而增加，直至达到一定水平。然而，对于病变更严重的主动脉，氧消耗又会下降。在研究的第二部分，测量了从兔子主动脉内膜 - 中膜分离出的泡沫细胞和平滑肌细胞组分的氧消耗。这些测量结果表明，分离出的泡沫细胞的氧消耗比分离出的平滑肌细胞高两倍。该研究提出，病变较轻的主动脉氧消耗增加反映了动脉壁中泡沫细胞比例的增加。随着病变发展以及内膜中泡沫细胞数量增加，氧和营养物质向病变更深部位的有效扩散能力可能变得不足，导致观察到病变更严重样本的细胞氧消耗下降。可能会发生缺氧性细胞损伤和进一步的组织反应，起始病变的愈合可能会受到危及。
