Vascular Muscle Calcium Channel Modulation in Hypertension
Vascular Muscle Calcium Channel Modulation in Hypertension
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高血压中的血管肌肉钙通道调节
DOI：
10.1097/00005344-198900146-00011
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发表时间：
1989
影响因子：
3
通讯作者：
A. Puga
中科院分区：
文献类型：
--
作者：
K. Hermsmeyer;M. Sturek;W. Marvin;R. Mason;A. Puga
自发性高血压大鼠（SHR）血管肌细胞膜改变的迹象，与他们的京都-Wistar血压正常对照组（WKY）相比，导致了钙通道的进一步研究。该实验室以前的工作表明，SHR中持久（L型）钙通道开放的可能性增加，表明数量或调节的差异。这些实验是在新生大鼠的奇静脉上进行的，因为该制备物已被电生理学、电生理学和收缩参数表征。通过L-型钙通道的二价（向内）离子电流更容易由钡携带，而不是由钙携带，这一特征对于瞬时（T）通道是不正确的。由于SHR的L/T钙通道比例增加，因此钡对SHR内向电流振幅的替代作用比WKY更明显。这种持续的L-型钙电流的增加，在新生动物的静脉侧没有出现血压升高，这表明遗传膜改变，可能有助于血管肌肉膜的变化，在血压升高的发展中很重要。带状血管肌细胞与心肌细胞的描述和分化，以及老年动物中两者混淆的可能性。在这些奇静脉细胞中T型钙电流的优势，这可能与快速自发性收缩的优势，提供了一个令人信服的理由，选择奇静脉钙通道比较，以建立高血压的细胞水平的病因。
Indications of membrane alterations in vascular muscle cells of spontaneously hypertensive rats (SHR), compared to their Kyoto-Wistar nomotensive controls (WKY), have led to further investigation of calcium channels. Previous work from this laboratory had shown the increased probability for opening of the longer-lasting (L-type) calcium channels in SHR, suggesting differences in number or modulation. These experiments have been carried out on the azygos vein of neonatal rats because that preparation has been characterized electro-physiologically, pharmacologically, and by contractile parameters. Divalent (inward) ion currents through the L-type calcium channels are more readily carried by barium than by calcium, a characteristic that is not true for the transient (T) channels. Because there is an increased ratio of L to T calcium channels in SHR, the substitution of barium for calcium is more apparent for inward current amplitude in SHR than in WKY. This increase in the sustained L-type calcium currents, appearing without increased blood pressure on the venous side in newborn animals, is suggestive of a genetic membrane alteration that could contribute to vascular muscle membrane changes important in the development of increased blood pressure. Description and differentiation of the ribbon shaped vascular muscle cells from cardiac muscle cells, and the potential for confusion of the two in older animals, was addressed. The predominance of T-type calcium currents in these azygos vein cells, which is likely to correlate with the predominance of rapid spontaneous contractions, offers a compelling reason for selection of azygos veins in Ca2+ channel comparisons to establish etiologic factors at the cell level in hypertension.