Lazzarino G, Vagnozzi R, Tavazzi B, Pastore F S, Di Pierro D, Siragusa P, Belli A, Giuffré R, Giardina B
Department of Experimental Medicine and Biochemical Sciences, University of Rome Tor Vergata, Italy.
Free Radic Biol Med. 1992 Nov;13(5):489-98. doi: 10.1016/0891-5849(92)90143-5.
Short-term incomplete cerebral ischemia (5 min) was induced in the rat by the bilateral clamping of the common carotid arteries. Reperfusion was obtained by removing carotid clamping and was carried out for the following 10 min. Animals were sacrificed either at the end of ischemia or reperfusion. Controls were represented by a group of sham-operated rats. Peripheral venous blood samples were withdrawn from the femoral vein from rats subjected to cerebral reperfusion 5 min before ischemia, at the end of ischemia, and 10 min after reperfusion. Neutralized perchloric acid extracts of brain tissue were analyzed by a highly sensitive high-performance liquid chromatography (HPLC) method for the direct determination of malondialdehyde, oxypurines, nucleosides, nicotinic coenzymes, and high-energy phosphates. In addition, plasma concentrations of malondialdehyde, hypoxanthine, xanthine, inosine, uric acid, and adenosine were determined by the same HPLC technique. Incomplete cerebral ischemia induced the appearance of a significant amount (8.05 nmol/g w.w.; SD = 2.82) of cerebral malondialdehyde (which was undetectable in control animals) and a decrease of ascorbic acid. A further 6.6-fold increase of malondialdehyde (53.30 nmol/g w.w.; SD = 17.77) and a 18.5% decrease of ascorbic acid occurred after 10 min of reperfusion. Plasma malondialdehyde, which was present in minimal amount before ischemia (0.050 mumol/L; SD = 0.015), significantly increased after 5 min of ischemia (0.277 mumol/L; SD = 0.056) and was strikingly augmented after 10 min of reperfusion (0.682 mumol/L; SD = 0.094). A similar trend was observed for xanthine, uric acid, inosine, and adenosine, while hypoxanthine reached its maximal concentration after 5 min of incomplete ischemia, being significantly decreased after reperfusion. From the data obtained, it can be concluded that tissue concentrations of malondialdehyde and ascorbic acid, and plasma levels of malondialdehyde, oxypurines, and nucleosides, reflect both the oxygen radical-mediated tissue injury and the depression of energy metabolism, thus representing early biochemical markers of short-term incomplete brain ischemia and reperfusion in the rat. In particular, these results suggest the possibility of using the variation of malondialdehyde, oxypurines, and nucleosides in peripheral blood as a potential biochemical indicator of reperfusion damage occurring to postischemic tissues.
通过双侧夹闭大鼠颈总动脉诱导短期不完全性脑缺血（5分钟）。去除颈动脉夹闭实现再灌注，并持续10分钟。在缺血结束时或再灌注结束时处死动物。对照组为一组假手术大鼠。在缺血前5分钟、缺血结束时以及再灌注后10分钟，从接受脑再灌注的大鼠股静脉采集外周静脉血样本。采用高灵敏度高效液相色谱（HPLC）法分析脑组织的中和过氯酸提取物，以直接测定丙二醛、氧化嘌呤、核苷、烟碱辅酶和高能磷酸盐。此外，采用相同的HPLC技术测定血浆中丙二醛、次黄嘌呤、黄嘌呤、肌苷、尿酸和腺苷的浓度。不完全性脑缺血导致出现大量（8.05 nmol/g湿重；标准差=2.82）脑丙二醛（对照组动物中未检测到），同时抗坏血酸减少。再灌注10分钟后，丙二醛进一步增加6.6倍（53.30 nmol/g湿重；标准差=17.77），抗坏血酸减少18.5%。缺血前血浆丙二醛含量极少（0.050 μmol/L；标准差=0.015），缺血5分钟后显著增加（0.277 μmol/L；标准差=0.056），再灌注10分钟后显著升高（0.682 μmol/L；标准差=0.094）。次黄嘌呤、尿酸、肌苷和腺苷呈现类似趋势，而次黄嘌呤在不完全缺血5分钟后达到最高浓度，再灌注后显著降低。从获得的数据可以得出结论，丙二醛和抗坏血酸的组织浓度以及丙二醛、氧化嘌呤和核苷的血浆水平，既反映了氧自由基介导的组织损伤，也反映了能量代谢的抑制，因此代表了大鼠短期不完全性脑缺血和再灌注的早期生化标志物。特别是，这些结果表明，外周血中丙二醛、氧化嘌呤和核苷的变化有可能作为缺血后组织发生再灌注损伤的潜在生化指标。
