Morphology and metabolism of an aortic intima-media preparation in which an intact endothelium is preserved.
Morphology and metabolism of an aortic intima-media preparation in which an intact endothelium is preserved.
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保留完整内皮的主动脉内膜中层制剂的形态和代谢。
DOI：
10.1172/jci108321
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发表时间：
1976
期刊：
影响因子：
--
通讯作者：
Albert I. WNEmGRAD
中科院分区：
文献类型：
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作者：
ANrHoNY D. Morrison;Leonard BERwICK;L. Orci;Albert I. WNEmGRAD
兔主动脉“内膜-介质”的体外制备先前显示出稳定的呼吸和葡萄糖代谢速率，以及被认为是该组织代谢特征的高有氧糖酵解速率，并进行了电子显微镜检查。在与现在常用的条件相似的条件下，在主动脉剥离脂肪组织和外膜后立即检查的样本中，内皮细胞结构出现了明显而广泛的改变，包括细胞完整性的丧失。血管平滑肌细胞保持正常的电镜外观。随后，在pH为7.4的KRB（克雷布斯-林格碳酸氢盐）中用5 mM葡萄糖孵育期间，在通常用于该制剂研究的条件下，管腔表面的大片内皮被迅速剥离，剩余的内皮细胞表现出广泛的超微结构改变。然而，平滑肌细胞继续保持正常的电镜外观。建立了一种制备兔主动脉内膜-中膜段的方法，该方法保留了与原位固定组织相似的完整内皮层。在KRB中5 mM葡萄糖，pH 7.4，气相5% CO2/95% O2，含6%牛血清白蛋白1小时的孵育过程中，完整的主动脉内膜-介质制备保持了基本不变的EM外观，并表现出线性呼吸速率。在这些条件下，完整的主动脉内膜-中膜制备比我们之前的制备或其他报道的主动脉内膜-中膜制备中观察到的O2摄取率和葡萄糖摄取率明显更高。在体外培养期间，完整的主动脉内膜中膜不表现出高的有氧糖酵解率，而这被认为是兔、大鼠和猪主动脉内膜中膜代谢的特征。此外，巴斯德效应的强度远远大于在其他主动脉内膜-中膜制剂中观察到的效果。数据表明，主动脉内膜-中膜的组成细胞可能从呼吸中获得其能量需求的主要部分；他们提出了进一步的问题，即在体外培养主动脉内膜介质制剂时观察到的高有氧糖酵解率的意义，他们建议在这种制剂中记录内皮的EM外观是可取的。
An in vitro preparation of rabbit aortic "intima-media" previously shown to exhibit stable rates of respiration and glucose metabolism and the high rate of aerobic glycolysis considered characteristic of the metabolism of this tissue was subjected to electron microscopic examination. In samples examined immediately after the aortae were dissected free of adipose tissue and adventitia, under conditions similar to those now in common use, marked and widespread alterations in endothelial cell structure were present, including loss of cell integrity. The vascular smooth muscle cells retained a normal electron microscopic (EM) appearance. During subsequent incubation with 5 mM glucose in Krebs-Ringer bicarbonate (KRB), pH 7.4, under the conditions usually employed in studies of this preparation, large zones of the luminal surface were rapidly denuded of endothelium, and the remaining endothelial cells exhibited a wide range of ultrastructural alterations. The smooth muscle cells, however, continued to maintain a normal EM appearance. A method was developed to prepare segments of rabbit aortic intima-media which retained an intact layer of endothelium resembling that observed in tissue fixed in situ. During a 1-h incubation with 5 mM glucose in KRB, pH 7.4, gas phase 5% CO2/95% O2, containing 6% bovine serum albumin, the intact aortic intima-media preparation retains an essentially unmodified EM appearance and exhibits linear rates of respiration. Under these conditions the intact aortic intima-media preparation exhibits significantly higher rates of O2 uptake and glucose uptake than those observed in our previous preparation or in other reported aortic intima-media preparations. The intact aortic intima-media does not exhibit the high rate of aerobic glycolysis during in vitro incubation that has been considered characteristic of the metabolism of rabbit, rat, and swine aortic intima-media. In addition, the magnitude of the Pasteur effect was far greater than that observed in other aortic intima-media preparations. The data suggest that component cells of the aortic intima-media may derive a major fraction of their energy requirements from respiration; they raise further questions concerning the significance of the high rate of aerobic glycolysis observed when aortic intima-media preparations are incubated in vitro, and they suggest that documentation of the EM appearance of the endothelium in such preparations is desirable.