Adaptive changes in control of blood vessel tone

慢性全身血管内高压是发病率和死亡率的主要原因。 高体循环压定义为收缩压/舒张压>140/ >90 mmHg。 收缩压是心脏收缩时血管中的压力，舒张压是心脏舒张时的压力。 血管直径是对全身血管内压力的主要影响，其由血管壁的主要成分平滑肌细胞的大小变化决定。 例如，当平滑肌缩短或收缩时，血管的直径变小。 同样，当平滑肌松弛和伸长时，血管扩张（即血管直径增加）。 血管直径的增加降低了血流阻力，这导致全身血管内压降低。 另一方面，血管直径的减小导致血管阻力的增加。 这种流动阻力的增加可能导致血液流量降低，营养物质和氧气的输送减少，以及废物从器官中的去除，从而降低组织的最佳功能，有时导致细胞死亡。 在我们的实验室中，我们感兴趣的是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、血管腔直径、局部血流、血管电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液动力学、血流量、血管传导性和僵硬度的影响，以确定血管内压力的慢性升高如何表现出对血管反应和功能的有害影响。 我们的研究结果应该提供深入了解高全身压力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大大促进我们对血管如何适应的理解，或者在异常和压力条件下受到负面影响。 我们的工作成果将提高马达加斯加人的生活质量。

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.