Hashimoto Takashi, Yonetani Masahiko, Nakamura Hajime
Department of Pediatrics, Kobe University Graduate School of Medicine, Japan.
Kobe J Med Sci. 2003;49(3-4):83-91.
We hypothesized that selective brain hypothermia (SBHT) decreases production of hydroxyl radicals (*OH) induced by hypoxia-ischemia (H-I) and reperfusion and attenuates neuronal damage in neonatal rat brain. Anesthetized 7-day-old rats were divided into a normothermia (NT) group (n=6) and a SBHT group (n=7) and subjected to 90-min H-I, followed by a 90-min recovery period. Brain temperature (BT) was regulated by a water-cooled metallic plate placed under the head. The BT of the SBHT group was set at 31.0+/-1.0 degrees C during the H-I and recovery period. Microdialysis and the salicylate-trapping method were used to detect *OH in the striatum. Neuronal damage was quantified by counting the surviving neurons at 120 hr after reperfusion. The NT group had significant increases in 2,3-dihydroxybenzoic acid (DHBA) (223+/-166%) and 2,5-DHBA (321+/-153%) above baseline levels. The increases in 2,3-DHBA (127+/-40%) and 2,5-DHBA (133+/-33%) were significantly lower (p < 0.01) in the SBHT group. The number of surviving neurons was decreased significantly in the NT group but not in the SBHT group. We conclude that SBHT reduces *OH production during H-I and reperfusion and has protective effects against neuronal damage.
我们假设选择性脑低温（SBHT）可减少缺氧缺血（H-I）和再灌注诱导产生的羟自由基（OH），并减轻新生大鼠脑内的神经元损伤。将7日龄麻醉大鼠分为正常体温（NT）组（n = 6）和SBHT组（n = 7），使其经历90分钟的H-I，随后是90分钟的恢复期。脑温（BT）通过置于头部下方的水冷金属板进行调节。在H-I和恢复期，SBHT组的BT设定为31.0±1.0摄氏度。采用微透析和水杨酸盐捕获法检测纹状体内的OH。通过对再灌注后120小时存活神经元进行计数来量化神经元损伤。NT组的2,3-二羟基苯甲酸（DHBA）（223±166%）和2,5-DHBA（321±153%）较基线水平显著增加。SBHT组中2,3-DHBA（127±40%）和2,5-DHBA（133±33%）的增加显著更低（p < 0.01）。NT组存活神经元数量显著减少，而SBHT组未减少。我们得出结论，SBHT可减少H-I和再灌注期间的*OH产生，并对神经元损伤具有保护作用。
