Werchan P M, Schadt J C, Fanton J W, Laughlin M H
Crew Technology Division, Armstrong Laboratory, Brooks AFB, TX 78235-5000.
Aviat Space Environ Med. 1994 Jun;65(6):501-9.
This study had two purposes. First, the use of Transonic flowprobes placed on the common carotid and internal carotid arteries of seven male baboons was evaluated for measuring cerebral blood flow (BF) during +Gz stress. The approach was to compare BF's obtained with these flowprobes to microsphere measurements of total cerebral BF. The second purpose was to measure regional variations in cerebral and spinal cord BF during +Gz to test the hypothesis that +Gz produces a differential perfusion deficit throughout the central nervous system so that BF's at the superior portion of the brain are decreased more than in areas of the brain that are nearer to the heart. The results indicate that internal carotid artery and microsphere measurements of total brain BF were related so that the relative decrease in internal carotid artery BF was consistently comparable to that measured with the labeled microsphere technique. Thus, Transonic flowprobes placed on the internal carotid artery of the baboon give reliable estimates of cerebral BF during +Gz stress. The microsphere BF data demonstrated that there were no regional differences in the relative decrease in BF measured in the brain or spinal cord during +Gz. We conclude that our results do not support the hypothesis of a gradient of BF deficit within the brain or spinal cord during +Gz.
本研究有两个目的。其一，评估将Transonic血流探头置于七只雄性狒狒的颈总动脉和颈内动脉上，用于测量+Gz应激期间脑血流量（BF）的情况。方法是将这些血流探头测得的脑血流量与全脑BF的微球测量值进行比较。第二个目的是测量+Gz期间脑和脊髓BF的区域差异，以检验以下假设：+Gz会在整个中枢神经系统产生不同程度的灌注不足，使得脑上部的BF下降幅度大于靠近心脏部位的脑区。结果表明，颈内动脉测量值与全脑BF的微球测量值相关，因此颈内动脉BF的相对下降与标记微球技术测量的结果始终具有可比性。因此，置于狒狒颈内动脉上的Transonic血流探头能够可靠地估计+Gz应激期间的脑BF。微球BF数据表明，+Gz期间脑或脊髓中测量的BF相对下降不存在区域差异。我们得出结论，我们的结果不支持+Gz期间脑或脊髓内存在BF不足梯度的假设。
