Hypoxic preconditioning enhances renal superoxide dismutase levels in rats
Hypoxic preconditioning enhances renal superoxide dismutase levels in rats
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DOI：
10.1113/jhysiol.2003.045559
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发表时间：
2003-10-15
影响因子：
5.5
通讯作者：
Wu, MS
中科院分区：
文献类型：
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作者：
Chen, CF;Tsai, SY;Wu, MS
肾缺血在肾脏中释放出活性氧簇(ROS)。我们假设，慢性低氧大鼠的肾脏对ROS的侮辱更具抵抗力。因此，我们比较了保持在海平面(SL)的大鼠和那些通过在海拔5500米的高原舱中暴露15小时/天(-1)连续4周而适应低氧(缺氧适应，HA)的大鼠。肾内注射黄嘌呤(X，0.75 mg·kg~(-1))和黄嘌呤氧化酶(XO，24.8 mU·kg~(-1))。采用荧光素增强型化学发光法检测肾静脉血和肾表面自由基含量。X-XO治疗后SL和HA大鼠肾静脉血中分别检出26.05(+/-4.36)×10(4)和10.98(+/-1.79)×10(4)个，差异有统计学意义。SL组大鼠肾表面自由基数为12.77(+/-1.64)×10(4)，HA组为8.47(+/-0.42)×10(4)，差异有统计学意义。X-XO给药后，两组大鼠尿量、尿Na+、K+和蛋白排泄量均显著增加。但对SL大鼠的影响大于HA大鼠。两组大鼠肾脏的脂质过氧化反应无明显差异。最后，我们发现HA大鼠肾组织中的超氧化物歧化酶(SOD)活性和超氧化物歧化酶mRNA的活性都较高。结论：慢性低氧后大鼠肾脏对自由基的反应减弱，超氧化物歧化酶可能在保护HA大鼠免受氧化应激中起重要作用。
Renal ischaemia releases reactive oxygen species (ROS) in the kidneys. We hypothesized that the kidneys are more resistant to the insult of ROS in chronically hypoxic rats. We thus compared rats kept at sea level (SL) and those that had been adapted to hypoxia (hypoxia adapted, HA) by exposure to an altitude of 5500 m in an altitude chamber for 15 h day(-1) for 4 weeks. Xanthine (X, 0.75 mg kg(-1)) and xanthine oxidase (XO, 24.8 mU kg(-1)) were injected intrarenally. A lucigenin-enhanced chemiluminescence method was employed to detect the amount of free radicals in renal venous blood samples and on the kidney surface. In the renal venous blood samples, 26.05 (+/- 4.36) X 10(4) and 10.98 (+/- 1.79) X 10(4) counts were detected in the SL and HA rats, respectively, after X-XO treatment; these figures were significantly different. On the kidney surface of the SL rats, the free radical count amounted to 12.77 (+/- 1.64) x 10(4), while that in the HA rats was 8.47 (+/- 0.42) x 10(4); these figures were also significantly different. There was a significant increase in urine volume and urinary excretion of Na+, K+ and protein after X-XO administration in both groups of rats. However, the effect was greater for the SL rats than for the HA rats. The lipid peroxidation of the kidneys was not significantly different in the two groups of rats. Finally, we found that the activity of superoxide dismutase (SOD) and SOD mRNA were higher in the renal tissue of HA rats. We conclude that the renal response to free radicals is attenuated after chronic hypoxia in rats, and that SOD might play an important role in protecting HA rats from oxidative stress.