Differential development of umbilical and systemic arteries. II. Contractile proteins.
Differential development of umbilical and systemic arteries. II. Contractile proteins.
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脐动脉和全身动脉的发育差异。
DOI：
10.1152/ajpregu.1998.274.6.r1815
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发表时间：
1998
期刊：
影响因子：
--
通讯作者：
Rosenfeld,CR
中科院分区：
文献类型：
--
作者：
Arens,Y;Chapados,RA;Cox,BE;Kamm,KE;Rosenfeld,CR
在胎羊中，脐对ANG II的反应性超过全身血管反应性。胎儿全身血管平滑肌（VSM）表现出不成熟的表型，收缩蛋白含量减少，低200 kDa肌球蛋白重链（MHC）SM 2，和显着的非肌肉MHC-B表达，而脐带VSM表型是不完全描述。我们检验了血管反应性的差异可以反映VSM表型的差异这一假设。肌动蛋白，MHC，MHC亚型，和主动应力进行了比较，在条股动脉和主动脉从近足月胎儿（n= 12）和成人（n= 12）羊的外部和腹内脐动脉。胎儿股动脉和主动脉的肌动蛋白含量（分别为7.37 ± 1.4和7.53 ± 0.7对21.6 ± 2.2 μg/mg湿重）低于（P≤ 0.006）脐外动脉，MHC含量（分别为3.17 ± 0.4和2.84 ± 0.3对7.16 ± 0.7）。而204-和200-kDa的MHC同样表达在胎儿全身动脉，脐动脉和成人动脉主要表达的204-kDa亚型（SM 1），只有胎儿全身VSM表达MHC-B。胎儿体动脉应力和肌球蛋白轻链磷酸化水平低于脐动脉和成人动脉（P< 0.001）。与脐动脉和成人动脉相比，胎儿系统性VSM在生化和功能上都不成熟，因此脐VSM在蛋白表达和功能上表现出与成人VSM相似的早熟成熟。
In fetal sheep, umbilical responsiveness to ANG II exceeds systemic vascular responsiveness. Fetal systemic vascular smooth muscle (VSM) exhibits an immature phenotype with decreased contractile protein contents, low 200-kDa myosin heavy chain (MHC) SM2, and significant nonmuscle MHC-B expression, whereas umbilical VSM phenotype is incompletely described. We tested the hypothesis that differences in vascular responsiveness could reflect dissimilarities in VSM phenotype. Actin, MHC, MHC isoforms, and active stresses were compared in strips of femoral arteries and aorta from near-term fetal (n= 12) and adult (n= 12) sheep to those in external and intra-abdominal umbilical arteries. Actin contents in fetal femoral artery and aorta were less (P≤ 0.006) than in external umbilical artery (7.37 ± 1.4 and 7.53 ± 0.7 vs. 21.6 ± 2.2 μg/mg wet wt, respectively) as were MHC contents (3.17 ± 0.4 and 2.84 ± 0.3 vs. 7.16 ± 0.7, respectively). Whereas 204- and 200-kDa MHC were expressed equally in fetal systemic arteries, umbilical and adult arteries predominantly expressed the 204-kDa isoform (SM1); only fetal systemic VSM expressed MHC-B. Fetal systemic artery stresses and myosin light chain phosphorylation were less than those in umbilical and adult arteries (P< 0.001). Compared with umbilical and adult arteries, fetal systemic VSM is biochemically and functionally immature and thus umbilical VSM demonstrates precocious maturation resembling adult VSM in protein expression and function.