Drummond Heather A, Stec David E
Department of Physiology and Biophysics, Center for Excellence in Cardiovascular-Renal Research, University of Mississippi Medical Center, Jackson, MS, 39216-4505.
J Nephrol Res. 2015 Jun;1(1):1-9. doi: 10.17554/j.issn.2410-0579.2015.01.12. Epub 2015 Jun 26.
Pressure-induced constriction (also known as the "myogenic response") is an important mechanodependent response in small renal arteries and arterioles. The response is initiated by vascular smooth muscle cell (VSMC) stretch due to an increase in intraluminal pressure and leads to vasoconstriction. The myogenic response has two important roles as a mechanism of local blood flow autoregulation and protection against systemic blood pressure-induced microvascular damage. However, the molecular mechanisms underlying initiation of myogenic response are unresolved. Although several molecules have been considered initiators of the response, our laboratory has focused on the role of degenerin proteins because of their strong evolutionary link to mechanosensing in the nematode. Our laboratory has addressed the hypothesis that certain degenerin proteins act as mechanosensors in VSMCs. This article discusses the importance of a specific degenerin protein, β Epithelial Na Channel (βENaC), in pressure-induced vasoconstriction, renal blood flow and susceptibility to renal injury. We propose that loss of the renal myogenic constrictor response delays the correction of renal blood flow that occurs with fluctuations in systemic pressure, which allows pressure swings to be transmitted to the microvasculature, thus increasing the susceptibility to renal injury and hypertension. The role of βENaC in myogenic regulation is independent of tubular βENaC and thus represents a non-tubular role for βENaC in renal-cardiovascular homeostasis.
压力诱导的收缩(也称为“肌源性反应”)是肾小动脉和微动脉中一种重要的机械依赖性反应。这种反应是由管腔内压力升高导致血管平滑肌细胞(VSMC)拉伸引发的,并导致血管收缩。肌源性反应作为局部血流自动调节和抵御全身血压诱导的微血管损伤的机制,具有两个重要作用。然而,肌源性反应起始的分子机制尚未明确。尽管有几种分子被认为是该反应的启动因子,但由于我们实验室发现退化蛋白与线虫的机械传感有很强的进化联系,因此我们将重点放在了退化蛋白的作用上。我们实验室探讨了特定退化蛋白β上皮钠通道(βENaC)在压力诱导的血管收缩、肾血流量和肾损伤易感性中的重要性这一假设。我们提出,肾肌源性收缩反应的丧失会延迟肾血流量随全身压力波动的校正,这使得压力波动传递到微血管,从而增加肾损伤和高血压的易感性。βENaC在肌源性调节中的作用独立于肾小管βENaC,因此代表了βENaC在肾-心血管稳态中的非肾小管作用。