We hypothesized that aging is characterized by a reduced release of nitric oxide (NO) in response to shear stress in resistance vessels. Mesenteric arterioles and arteries of young (6 mo) and aged (24 mo) male Fischer 344 rats were isolated and cannulated. Shear stress (15 dyn/cm(2))-induced dilation was significantly reduced and shear stress (1, 5, 10, and 15 dyn/cm(2))-induced increases in pe...

Alterations in the functions of vascular endothelial cells (ECs) induced by fluid shear stress may play a pivotal role in both the development and prevention of vascular diseases. We found that DNA synthesis of bovine aortic and human umbilical vein ECs, determined by [H]thymidine incorporation, was inhibited by steady laminar shear stress (5 and 30 dyne/cm). This growth inhibition due to shear...

Blood vessels alter their morphology and function in response to changes in blood flow, and their responses are based on blood flow detection by the vascular endothelium. Endothelial cells (ECs) covering the inner surface of blood vessels sense shear stress generated by flowing blood and transmit the signal into the interior of the cell, which evokes a cellular response. The EC response to shea...

Shear stress caused by blood flow is a potent physiological stimulus for the generation of nitric oxide (NO) in endothelial cells, which is believed to derive from the up-regulation and post-transcriptional activation of endothelial constitutive NO synthase (ecNOS). However, it has yet to be demonstrated that inducible NO synthase (iNOS) plays a significant role in shear stress-induced NO produ...

Circulating tumor cells (CTCs) are the primary targets of cancer treatment as they cause distal metastasis. However, how CTCs response to exercise-induced high shear stress is largely unknown. To study the effects of hemodynamic microenvironment on CTCs, we designed a microfluidic circulatory system that produces exercise relevant shear stresses. We explore the effects of shear stresses on brea...

OBJECTIVE Low wall shear stress has been implicated in atherogenesis throughout the arterial tree, including the right coronary artery (RCA). The objective of this study was to determine the level of covariation of intimal thickness and wall shear stress in the human RCA. METHODS AND RESULTS Postmortem histological measurements of intimal thickness were compared with wall shear stresses calcu...

the effects of physical, thermal and mechanical parameters on curing microthermal residual stresses are studied, based on the energy method, to present a theoretical solution for prediction of residual stress felds. a fnite element analysis is developed to compare the theoretical and numerical results together. there is found to be a good agreement between the results of the two methods. howeve...

The effects of an overlapping stenosis on blood flow characteristics in a narrow artery have been investigated. To account for the non-Newtonian behavior, blood has been represented by a Casson fluid. The equation describing the flow has been solved and the expressions for the flow characteristics, namely, the impedance, the wall shear stress, the shear stress at the stenosis throats and the sh...