Sakamoto T, Monafo W W
Department of Surgery, Washington University School of Medicine, St. Louis, Missouri 63110.
Am J Physiol. 1989 Sep;257(3 Pt 2):H785-90. doi: 10.1152/ajpheart.1989.257.3.H785.
[14C]butanol tissue uptake was used to measure simultaneously regional blood flow in three regions of the brain (cerebral and cerebellar hemispheres and brain stem) and in five levels of the spinal cord in 10 normothermic rats (group A) and in 10 rats in which rectal temperature had been lowered to 27.7 +/- 0.3 degrees C by applying ice to the torso (group B). Pentobarbital sodium anesthesia was used. Mean arterial blood pressure varied minimally between groups as did arterial pH, PO2, and PCO2. In group A, regional spinal cord blood flow (rSCBF) varied from 49.7 +/- 1.6 to 62.6 +/- 2.1 ml.min-1.100 g-1; in brain, regional blood flow (rBBF) averaged 74.4 +/- 2.3 ml.min-1.100 g-1 in the whole brain and was highest in the brain stem. rSCBF in group B was elevated in all levels of the cord by 21-34% (P less than 0.05). rBBF, however, was lowered by 21% in the cerebral hemispheres (P less than 0.001) and by 14% in the brain as a whole (P less than 0.05). The changes in calculated vascular resistance tended to be inversely related to blood flow in all tissues. We conclude that rBBF is depressed in acutely hypothermic pentobarbital sodium-anesthetized rats, as has been noted before, but that rSCBF rises under these experimental conditions. The elevation of rSCBF in hypothermic rats confirms our previous observations.
采用[14C]丁醇组织摄取法，同时测定了10只体温正常大鼠（A组）和10只通过对躯干敷冰使直肠温度降至27.7±0.3℃的大鼠（B组）脑的三个区域（大脑半球、小脑半球和脑干）以及脊髓五个节段的局部血流量。采用戊巴比妥钠麻醉。两组间平均动脉血压、动脉pH、PO2和PCO2的变化极小。在A组中，脊髓局部血流量（rSCBF）在49.7±1.6至62.6±2.1 ml·min-1·100 g-1之间；在脑内，全脑局部血流量（rBBF）平均为74.4±2.3 ml·min-1·100 g-1，且在脑干中最高。B组所有脊髓节段的rSCBF均升高了21%-34%（P<0.05）。然而，大脑半球的rBBF降低了21%（P<0.001），全脑降低了14%（P<0.05）。计算得出的血管阻力变化在所有组织中往往与血流量呈负相关。我们得出结论，正如之前所指出的，急性低温戊巴比妥钠麻醉大鼠的rBBF降低，但在这些实验条件下rSCBF升高。低温大鼠rSCBF的升高证实了我们之前的观察结果。
