Adaptive changes in control of blood vessel tone

慢性全身血管内高压是发病和死亡的主要原因。高体压定义为收缩压/舒张压>40 / bbb90mmhg。收缩压是心脏收缩时血管的压力，舒张压是心脏放松时的压力。血管直径是影响全身血管内压力的主要因素，它是由平滑肌细胞大小的变化决定的，平滑肌细胞是血管壁的主要成分。例如，当平滑肌缩短或收缩时，血管的直径就会变小。同样的道理，当平滑肌放松和延长时，血管扩张（即血管直径增加）。血管直径的增加减少了对血流的阻力，从而导致全身血管内压力的降低。另一方面，血管直径的减小导致血管阻力的增加。流动阻力的增加会导致血流量减少，营养物质和氧气的输送减少，器官废物的清除减少，从而降低组织的最佳功能，有时会导致细胞死亡。在我们的实验室，我们感兴趣的血管平滑肌和内皮细胞的功能，以及全身血管压力的控制。我们的目标是研究参与控制平滑肌功能、血管管腔直径、局部血流、血管传导和血管硬度的过程。我的计划是检查全身动脉血压升高对血流动力学、血流、血管传导和僵硬度的影响，以确定血管内压力的慢性升高如何显示其对血管反应和功能的有害影响。我们的研究结果将有助于深入了解高体压对血管生物学和行为的影响。从我们的研究中获得的信息将极大地促进我们对血管在异常和压力条件下如何适应或受到负面影响的理解。我们的研究成果将改善哺乳动物的生活质量。

Chronic high systemic intravascular pressure is a major cause of morbidity and mortality. High systemic pressure is defined as systolic/diastolic pressure >140/ >90 mmHg. The systolic pressure is the pressure in the vessels when the heart contracts and the diastolic pressure is the pressure when the heart relaxes. Blood vessel diameter, a major influence on systemic intravascular pressure, is determined by changes in the size of the smooth muscle cells, the main component of the vessel wall. For example, when smooth muscle shortens, or contracts, the diameter of the blood vessel becomes smaller. By the same token, when smooth muscle relaxes and lengthens, the blood vessels dilate (i.e. the diameter of the blood vessels increases). An increase in the diameter of blood vessels reduces resistance to blood flow which leads to lowering of systemic intravascular pressure. On the other hand, a reduction in the diameter of blood vessels leads to an increase in vascular resistance. This increase in resistance to flow can lead to a lower blood flow and reduced delivery of nutrients and oxygen and the removal of waste products from organs and thus reduce optimal function of the tissue, at times causing cell death. In our laboratory we are interested in the function of vascular smooth muscle and endothelial cells, and control of systemic vascular pressure. Our goals are to study the processes that are involved in the control of smooth muscle function, blood vessel lumen diameter, regional blood flow, vascular conductance and vascular stiffness. My plan is to examine the effect of elevation in systemic arterial blood pressure on haemodynamics, blood flow, vascular conductance and stiffness in order to determine how chronic increase in intravascular pressure manifests its detrimental effects on blood vessel response and function. Findings from our studies should provide insight into the effects of high systemic pressure on blood vessel biology and behavior. The information obtained from our studies will greatly advance our understanding of how vessels adapt, or are negatively impacted, under abnormal and stressful conditions. The outcome from our work will lead to improved quality of life in mammalians.