Cox Robert H, Fromme Samantha J, Folander Kimberly L, Swanson Richard J
Department of Pharmacology, Lankenau Institute for Medical Research, Main Line Health System, Wynnewood, Pennsylvania, USA.
Am J Hypertens. 2008 Feb;21(2):213-8. doi: 10.1038/ajh.2007.44. Epub 2008 Jan 3.
We have previously demonstrated differences in the gene expression of voltage-gated K v1.X channel alpha-subunits in arteries from Wistar-Kyoto rats (WKYs) and spontaneously hypertensive rats (SHRs). The purpose of this study was to test the hypothesis that these differences are also present at the protein level.
Proteins were isolated from the aorta, mesenteric (MAs) and tail arteries (TAs) of 12- to 15-week-old male WKY and SHR, and analyzed by immunoblotting. K(v) currents were recorded from MA myocytes by patch clamp methods.
Expression of Kv1.2, Kv1.5, and Kv2.1 was higher in MAs but was not different in aortas of SHRs as compared to WKYs. In the TA, expression of Kv1.2 and Kv1.5 was higher while that of Kv2.1 was lower in SHR compared to WKY. In the MA, the larger expression of an 80 kDa species of Kv1.2 in SHRs was associated with a lower expression of a 60 kDa species. Kv2.1 gene expression was larger in MAs from SHRs but not different in TAs. K(v) currents associated with Kv1.X and Kv2.1 channels were both larger in MA myocytes from SHRs but less than expected based upon differences in K(v) alpha-subunit protein expression.
For the MA, K(v) protein expression and current components between WKYs and SHRs were qualitatively consistent, but differences in gene and protein expression were not closely correlated. The higher expression of K(v) subunits in small mesenteric arteries (SMAs) of SHR would tend to maintain normal myogenic activity and vasoconstrictor reserve, and could be viewed as a form of homeostatic remodeling.
我们之前已经证明，Wistar - Kyoto大鼠（WKY）和自发性高血压大鼠（SHR）动脉中电压门控Kv1.X通道α亚基的基因表达存在差异。本研究的目的是验证这些差异在蛋白质水平也存在这一假设。
从12至15周龄雄性WKY和SHR的主动脉、肠系膜动脉（MA）和尾动脉（TA）中分离蛋白质，并通过免疫印迹法进行分析。采用膜片钳方法记录MA肌细胞中的K（v）电流。
与WKY相比，Kv1.2、Kv1.5和Kv2.1在SHR的MA中表达较高，但在主动脉中无差异。在TA中，与WKY相比，SHR中Kv1.2和Kv1.5的表达较高，而Kv2.1的表达较低。在MA中，SHR中80 kDa的Kv1.2物种表达较高与60 kDa物种的较低表达相关。Kv2.1基因在SHR的MA中表达较高，但在TA中无差异。与Kv1.X和Kv2.1通道相关的K（v）电流在SHR的MA肌细胞中均较大，但基于K（v）α亚基蛋白表达的差异，其小于预期。
对于MA，WKY和SHR之间的K（v）蛋白表达和电流成分在质量上是一致的，但基因和蛋白表达的差异没有密切相关。SHR的小肠系膜动脉（SMA）中K（v）亚基的较高表达倾向于维持正常的肌源性活动和血管收缩储备，并且可以被视为一种稳态重塑形式。
