Nitric Oxide Synthesis by Cultured Endothelial Cells Is Modulated by Flow Conditions

@article{citeulike:2244575, abstract = {Abstract In the present study, we examined the hypothesis that dynamic characteristics of flow modulate the production of vasoactive mediators, namely nitric oxide (NO) and endothelin-1 (ET-1), by human umbilical vein endothelial cells (HUVECs). Cells were exposed for 6 hours in a cone-and-plate apparatus to different types of flow: steady laminar, with shear stresses of 2, 8, and 12 dyne/cm2; pulsatile laminar, with shear stress from 8.2 to 16.6 dyne/cm2 and a frequency of 2 Hz; periodic laminar, with square wave cycles of 15 minutes and shear stress from 2 to 8 dyne/cm2; and turbulent, with shear stress of 8 dyne/cm2 on average. A second culture dish was kept in a normal incubator as a static control for each experiment. Laminar flow induced synthesis of NO by HUVECs that was dependent on shear-stress magnitude. Laminar shear stress at 8 dyne/cm2 also upregulated the level of NO synthase mRNA. As observed with steady laminar flow, pulsatile flow also induced an increase in NO release by endothelial cells. When HUVECs were subjected to step-change increases of laminar shear, a further increase of NO synthesis was observed, compared with steady laminar shear of the same magnitude. Turbulent flow did not upregulate NO synthase mRNA or increase NO release. Both laminar and turbulent shear stress reduced, although not significantly, ET-1 mRNA and ET-1 production compared with the static condition. These results indicate that local blood flow conditions modulate the production of vasoactive substances by endothelial cells. This may affect vascular cell functions such as nonthrombogenicity, regulation of blood flow, and vascular tone.}, author = {Noris, Marina and Morigi, Marina and Donadelli, Roberta and Aiello, Sistiana and Foppolo, Marco and Todeschini, Marta and Orisio, Silvia and Remuzzi, Giuseppe and Remuzzi, Andrea }, citeulike-article-id = {2244575}, journal = {Circ Res}, keywords = {flow, huvec, nitric\_oxide, no, oscillating, periodic, shear, steady, step, turbulent}, month = {April}, number = {4}, pages = {536--543}, posted-at = {2008-01-17 11:44:43}, priority = {3}, title = {Nitric Oxide Synthesis by Cultured Endothelial Cells Is Modulated by Flow Conditions}, url = {http://circres.ahajournals.org/cgi/content/abstract/76/4/536}, volume = {76}, year = {1995} }

TY - JOUR ID - citeulike:2244575 L3 - citeulike-article-id:2244575 TI - Nitric Oxide Synthesis by Cultured Endothelial Cells Is Modulated by Flow Conditions JF - Circ Res VL - 76 IS - 4 SP - 536 EP - 543 N2 - Abstract In the present study, we examined the hypothesis that dynamic characteristics of flow modulate the production of vasoactive mediators, namely nitric oxide (NO) and endothelin-1 (ET-1), by human umbilical vein endothelial cells (HUVECs). Cells were exposed for 6 hours in a cone-and-plate apparatus to different types of flow: steady laminar, with shear stresses of 2, 8, and 12 dyne/cm2; pulsatile laminar, with shear stress from 8.2 to 16.6 dyne/cm2 and a frequency of 2 Hz; periodic laminar, with square wave cycles of 15 minutes and shear stress from 2 to 8 dyne/cm2; and turbulent, with shear stress of 8 dyne/cm2 on average. A second culture dish was kept in a normal incubator as a static control for each experiment. Laminar flow induced synthesis of NO by HUVECs that was dependent on shear-stress magnitude. Laminar shear stress at 8 dyne/cm2 also upregulated the level of NO synthase mRNA. As observed with steady laminar flow, pulsatile flow also induced an increase in NO release by endothelial cells. When HUVECs were subjected to step-change increases of laminar shear, a further increase of NO synthesis was observed, compared with steady laminar shear of the same magnitude. Turbulent flow did not upregulate NO synthase mRNA or increase NO release. Both laminar and turbulent shear stress reduced, although not significantly, ET-1 mRNA and ET-1 production compared with the static condition. These results indicate that local blood flow conditions modulate the production of vasoactive substances by endothelial cells. This may affect vascular cell functions such as nonthrombogenicity, regulation of blood flow, and vascular tone. KW - flow KW - huvec KW - nitric_oxide KW - no KW - oscillating KW - periodic KW - shear KW - steady KW - step KW - turbulent AU - Noris, Marina AU - Morigi, Marina AU - Donadelli, Roberta AU - Aiello, Sistiana AU - Foppolo, Marco AU - Todeschini, Marta AU - Orisio, Silvia AU - Remuzzi, Giuseppe AU - Remuzzi, Andrea PY - 1995/04/01/ UR - http://circres.ahajournals.org/cgi/content/abstract/76/4/536 ER -