Thubrikar M J, Baker J W, Nolan S P
Department of Surgery, University of Virginia Medical Center, Charlottesville 22908.
Arteriosclerosis. 1988 Jul-Aug;8(4):410-20. doi: 10.1161/01.atv.8.4.410.
Atherosclerotic lesions commonly develop at arterial branch sites, which are also the sites of high arterial intramural stress produced by intraluminal pressure. We investigated the effect of reduced intramural stress on the development of atherosclerotic lesions. We exposed the origin of the left renal artery in five rabbits and the aortic bifurcation in another five, lowered the mean arterial pressure to 35 to 45 mm Hg, and poured a dental acrylic liquid around the branch to form a rigid cast. When the rabbits recovered and the arterial pressure increased to normal, the casts prevented the arteries from expanding, thereby maintaining a low intramural stress. These rabbits plus two unoperated, two sham-operated, two with silicone rubber casts placed at similar pressures, and four with casts placed at 95 mm Hg pressure were given a 2% cholesterol-enriched diet for 7 to 11 weeks, and then their arteries were examined. In all rabbits, atherosclerotic lesions developed at the origins of the intercostal, celiac, superior mesenteric, and both renal arteries, and at the aortic bifurcation, with these notable exceptions: no lesions developed at the origins of casted renal arteries or at the casted aortic bifurcations when the cast was placed at a low pressure. Measurements of the diameter and thickness of the aorta in the left renal branch and aortic bifurcation areas, with and without the casts, indicated that there was no significant narrowing of the aortic lumen or thinning of the aorta due to the cast. In conclusion, the inhibition of the development of atherosclerotic lesions appears to be associated with the reduction of arterial intramural stress.
动脉粥样硬化病变通常在动脉分支部位形成，这些部位也是管腔内压力产生高动脉壁内应力的部位。我们研究了降低壁内应力对动脉粥样硬化病变发展的影响。我们暴露了5只兔子的左肾动脉起始部和另外5只兔子的主动脉分叉处，将平均动脉压降至35至45毫米汞柱，并在分支周围灌注牙科丙烯酸液体以形成刚性铸型。当兔子恢复且动脉压升至正常时，铸型阻止动脉扩张，从而维持低壁内应力。给这些兔子加上2只未手术、2只假手术、2只在相似压力下放置硅橡胶铸型以及4只在95毫米汞柱压力下放置铸型的兔子喂食富含2%胆固醇的饮食7至11周，然后检查它们的动脉。在所有兔子中，肋间动脉、腹腔动脉、肠系膜上动脉以及双侧肾动脉的起始部和主动脉分叉处均出现了动脉粥样硬化病变，但有这些显著例外：当铸型置于低压时，铸型处理的肾动脉起始部或铸型处理的主动脉分叉处未出现病变。对有铸型和无铸型情况下左肾分支和主动脉分叉区域主动脉直径和厚度的测量表明，铸型并未导致主动脉管腔明显变窄或主动脉变薄。总之，动脉粥样硬化病变发展的抑制似乎与动脉壁内应力的降低有关。
