Ogoh Shigehiko, Washio Takuro, Sasaki Hiroyuki, Petersen Lonnie G, Secher Niels H, Sato Kohei
Department of Biomedical Engineering, Toyo University, Kawagoe, Japan;
Department of Biomedical Engineering, Toyo University, Kawagoe, Japan.
Am J Physiol Regul Integr Comp Physiol. 2016 Dec 1;311(6):R1255-R1261. doi: 10.1152/ajpregu.00325.2016. Epub 2016 Nov 2.
In supine humans the main drainage from the brain is through the internal jugular vein (IJV), but the vertebral veins (VV) become important during orthostatic stress because the IJV is partially collapsed. To identify the effect of this shift in venous drainage from the brain on the cerebral circulation, this study addressed both arterial and venous flow responses in the "anterior" and "posterior" parts of the brain when nine healthy subjects (5 men) were seated and flow was manipulated by hyperventilation and inhalation of 6% carbon dioxide (CO). From a supine to a seated position, both internal carotid artery (ICA) and IJV blood flow decreased (P = 0.004 and P = 0.002), while vertebral artery (VA) flow did not change (P = 0.348) and VV flow increased (P = 0.024). In both supine and seated positions the ICA response to manipulation of end-tidal CO tension was reflected in IJV (r = 0.645 and r = 0.790, P < 0.001) and VV blood flow (r = 0.771 and r = 0.828, P < 0.001). When seated, the decrease in ICA blood flow did not affect venous outflow, but the decrease in IJV blood flow was associated with the increase in VV blood flow (r = 0.479, P = 0.044). In addition, the increase in VV blood flow when seated was reflected in VA blood flow (r = 0.649, P = 0.004), and the two flows were coupled during manipulation of the end-tidal CO tension (supine, r = 0.551, P = 0.004; seated, r = 0.612, P < 0001). These results support that VV compensates for the reduction in IJV blood flow when seated and that VV may influence VA blood flow.
在仰卧位的人体中，大脑的主要引流途径是通过颈内静脉（IJV），但在体位性应激期间，椎静脉（VV）变得重要，因为颈内静脉会部分塌陷。为了确定这种大脑静脉引流变化对脑循环的影响，本研究探讨了9名健康受试者（5名男性）在坐位时，通过过度通气和吸入6%二氧化碳（CO）来操纵血流时，大脑“前部”和“后部”的动脉和静脉血流反应。从仰卧位到坐位，颈内动脉（ICA）和颈内静脉血流均减少（P = 0.004和P = 0.002），而椎动脉（VA）血流未改变（P = 0.348），椎静脉血流增加（P = 0.024）。在仰卧位和坐位时，颈内动脉对呼气末CO张力操纵的反应均反映在颈内静脉（r = 0.645和r = 0.790，P < 0.001）和椎静脉血流中（r = 0.771和r = 0.828，P < 0.001）。坐位时，颈内动脉血流的减少并未影响静脉流出，但颈内静脉血流的减少与椎静脉血流的增加相关（r = 0.479，P = 0.044）。此外，坐位时椎静脉血流的增加反映在椎动脉血流中（r = 0.649，P = 0.004），并且在呼气末CO张力操纵期间，这两种血流相互耦合（仰卧位，r = 0.551，P = 0.004；坐位，r = 0.612，P < 0.001）。这些结果支持，坐位时椎静脉可补偿颈内静脉血流的减少，并且椎静脉可能影响椎动脉血流。
