Seo Hyungseok, Lim Keun Ho, Choi Jae-Hyung, Jeong Sung-Moon
Department of Anesthesiology and Pain Medicine, College of Medicine, University of Ulsan, Asan Medical Center, Seoul, Republic of Korea.
Int J Dev Neurosci. 2013 Nov;31(7):616-23. doi: 10.1016/j.ijdevneu.2013.08.001. Epub 2013 Aug 16.
The aim of this study was to evaluate the effect of ischemic and hypoxic preconditioning on hypoxia-ischemia (HI) in the neonatal rat. Seven-day-old Sprague-Dawley rats were divided into four groups: control, sham, ischemic preconditioning, and hypoxic preconditioning. Ischemic preconditioning with a 10-min occlusion of the right carotid artery and hypoxic preconditioning with 4-h of hypoxia (8% oxygen) were performed 24-h before HI. For HI, all rats underwent right carotid artery ligature, followed by 2.5-h of hypoxia. Proton magnetic resonance spectroscopy ((1)H MRS) and TUNEL staining were evaluated at 1 and 7 days after HI. At 2 weeks after HI, all rats were sacrificed for morphological analysis. The lipid (Lip), N-acetyl aspartate (NAA), creatine (Cr), and choline-ratios were calculated and compared with TUNEL staining and brain morphologies. Both the ischemic and hypoxic preconditioning groups showed lower Lip/NAA and Lip/Cr ratios and morphological scores, and fewer TUNEL-positive cells than the control and sham groups (P < 0.05). There were no significant differences between the two preconditioning groups. In addition, the ratios correlated with the TUNEL staining and the degrees of morphological changes in all of the groups (P < 0.05). These results suggest that ischemic and hypoxic preconditioning in neonatal rats with HI similarly attenuate brain injury. Moreover, Lip/NAA and Lip/Cr ratios may be used as markers for assessing the extent of brain damage.
本研究的目的是评估缺血和缺氧预处理对新生大鼠缺氧缺血（HI）的影响。将7日龄的Sprague-Dawley大鼠分为四组：对照组、假手术组、缺血预处理组和缺氧预处理组。在HI前24小时进行10分钟右侧颈动脉闭塞的缺血预处理和4小时缺氧（8%氧气）的缺氧预处理。对于HI，所有大鼠均进行右侧颈动脉结扎，随后进行2.5小时缺氧。在HI后1天和7天评估质子磁共振波谱（（1）H MRS）和TUNEL染色。HI后2周，处死所有大鼠进行形态学分析。计算脂质（Lip）、N-乙酰天门冬氨酸（NAA）、肌酸（Cr）和胆碱比值，并与TUNEL染色和脑形态进行比较。与对照组和假手术组相比，缺血预处理组和缺氧预处理组的Lip/NAA和Lip/Cr比值及形态学评分均较低，TUNEL阳性细胞较少（P<0.05）。两个预处理组之间无显著差异。此外，所有组中的这些比值均与TUNEL染色及形态学变化程度相关（P<0.05）。这些结果表明，新生大鼠HI时的缺血和缺氧预处理同样能减轻脑损伤。此外，Lip/NAA和Lip/Cr比值可作为评估脑损伤程度的标志物。
