Mori K, Maeda T, Shiraishi Y, Kawai Y
Department of Physiology, Faculty of Medicine, Tottori University, Yonago, 683-8503 Japan.
Jpn J Physiol. 2001 Feb;51(1):71-9. doi: 10.2170/jjphysiol.51.71.
The effects of hypothermia on blood flow and neural activity were investigated in rabbit spinal cord during the acute phase of ischemia/reperfusion. Rabbits were exposed to ischemia for 10 or 40 min by occluding the abdominal aorta, using a balloon catheter. The body temperature was maintained either at 38 degrees C (normothermia) or 34 degrees C (hypothermia). Hyperperfusion was observed within 10 min after the cessation of ischemia in all rabbits exposed to ischemia. The magnitude of hyperperfusion in spinal cord blood flow (SCBF) was not significantly different between the 10 and 40 min ischemia rabbits, but the time for 50% recovery from the hyperperfusion was longer in the 40 min ischemia group (26.1 +/- 2.5 min) than in the 10 min group (15.1 +/- 2.1 min). The amplitude of evoked spinal cord potential decreased during ischemia and recovered to the baseline level during 8 h of reperfusion in the 10 min ischemia group. However, in the 40 min ischemia group, the amplitude was 40 +/- 8% of the baseline value after 8 h of reperfusion. Hypothermia prevented the delay of recovery from hyperperfusion and the reduction of evoked spinal cord potential. These results suggest that hypothermia plays a beneficial role in protecting tissue injury in the acute phase of ischemia/reperfusion in the spinal cord by shortening the time for recovery from postischemic hyperperfusion.
在缺血/再灌注急性期，研究了低温对兔脊髓血流和神经活动的影响。使用球囊导管阻断腹主动脉，使兔缺血10或40分钟。体温维持在38℃（正常体温）或34℃（低温）。所有缺血兔在缺血停止后10分钟内均观察到高灌注。缺血10分钟和40分钟的兔脊髓血流量（SCBF）高灌注幅度无显著差异，但40分钟缺血组从高灌注恢复50%的时间（26.1±2.5分钟）比10分钟组（15.1±2.1分钟）长。在10分钟缺血组，缺血期间诱发性脊髓电位幅度降低，再灌注8小时内恢复到基线水平。然而，在40分钟缺血组，再灌注8小时后幅度为基线值的40±8%。低温可防止高灌注恢复延迟和诱发性脊髓电位降低。这些结果表明，低温通过缩短缺血后高灌注恢复时间，在脊髓缺血/再灌注急性期保护组织损伤中发挥有益作用。
