Are there differences among characteristics of portions of human mesenteric artery trees?

在高血压和动脉粥样硬化等疾病状态下，血管病变的形成是以地区特有的方式发生的。大管道和小阻力动脉在器官灌流的调节中起着区域特异性的作用。采用体外培养方法，对大鼠肠系膜动脉床小动脉(内径小于90μm的S-SMC)和大动脉(L-SMC，内径800~900μm)来源的平滑肌细胞的形态和生长进行了研究。S-SMCs较小，呈两极形状；而L-SMCs多数较大，呈多边形。S-SMC内的肌动蛋白纤维从胞核开始呈两极排列，而L-SMC内的肌动蛋白纤维呈放射状。血清、血小板衍生生长因子-AB或机械牵张对S-SMC和L-SMC的[~3H]胸腺嘧啶核苷掺入均较大。加入血清或PDGF后，S-SMC的群体倍增时间明显短于L-SMC。因此，在同一血管床的小动脉和大动脉中，存在着不同的形态和生长表型。此外，我们进一步阐明了人肠系膜动脉平滑肌细胞中S-和L-SMCs的相同关系，并进一步阐明了人肠系膜动脉树的部分特征存在差异，这些分化标记包括钙桥蛋白和钙调蛋白，以及内源性和血管紧张素受体以及中等大小的细丝。

Vascular lesion formations in such disease states as hypertension and atherosclerosis occur in a district-specific manner. Large conduit and small resistance arteries play district-specific roles in the regulation of organ perfusion. Using a culture method, we studied the morphology and growth of smooth muscle cells derived from small arteries (S-SMCs, less than 90μm in internal diameter) and from larger arteries (L-SMCs, ranging from 800 to 900μm) of the rat mesenteric arterial bed. S-SMCs were smaller, bipolar-shaped ; in contrast, the majority of L-SMCs were larger, polygonal-shaped. Actin fibers within S-SMCs were oriented in a bipolar manner from the nuclei, whereas those within L-SMCs had a radial appearance. [3H]Thymidine incorporation induced by serum, platelet-derived growth factor-AB(PDGF), or mechanical stretch was greater in S- vs L-SMCs. The population doubling time measured after the addition of serum or PDGF was shorter in S- vs L-SMCs. Thus, distinct morphological and growth phenotypes of SMCs exist in small and larger arteries of the same vascular bed.Furthermore, we clarified that there are the same relationship between S- and L-SMCs in smooth muscle cells of human mesenteric arteries and furthermore that there are differences among characteristics of portions of human mesenteric artery trees using differentiation markers of calponin and caldesmon, and receptors of endotherins and angiotensins in addition of intermediated size filaments.