Effect of profound hypermagnesemia on spinal cord glucose utilization in rats.
Effect of profound hypermagnesemia on spinal cord glucose utilization in rats.
复制标题
严重高镁血症对大鼠脊髓葡萄糖利用的影响。
作者：
Szabo,MD;Crosby,G
本研究旨在探讨高镁血症对脊柱代谢率的影响。用2-[~(14)C]脱氧葡萄糖技术测定了瘫痪机械通气大鼠腰髓局部葡萄糖利用情况，这些大鼠接受70%一氧化二氮和静脉注射生理盐水(n=5)或硫酸镁(n=5)。高血镁组和对照组大鼠血浆镁浓度分别为6.75+/-0.5和0.9+/-0.5 mM(p<0.01)。高镁大鼠血压较低(88+/-1vs.130+/-4 mm Hg，p<0.01)，但血压仍在自我调节范围内。在高镁血症期间，脊髓灰质的葡萄糖利用率降低了26-45%，脊髓白质的葡萄糖利用率降低了53-63%。我们得出结论，镁是一种有效的脊髓代谢抑制剂，这一作用在脊髓白质中异常突出，是最近报道的镁疗法在脊髓缺血期间的有益效果的合理解释。
The purpose of our study was to investigate the effect of hypermagnesemia on spinal metabolic rate. The 2-[14C]deoxyglucose technique was used to measure regional glucose utilization in the lumbar spinal cord of paralyzed, mechanically ventilated rats receiving 70% nitrous oxide and an intravenous infusion of either saline (n = 5) or magnesium sulfate (n = 5). Plasma magnesium concentrations were 6.75 +/- 0.5 and 0.9 +/- 0.5 mM (p less than 0.01) in hypermagnesemic and control rats, respectively. Hypermagnesemic rats were hypotensive (88 +/- 1 vs. 130 +/- 4 mm Hg, p less than 0.01) but blood pressure remained within the autoregulatory range. Glucose utilization was reduced 26-45% in spinal gray matter and 53-63% in spinal white matter during hypermagnesemia. We conclude that magnesium is a potent spinal metabolic depressant and that this action, which is unusually prominent in spinal white matter, is a plausible explanation for the recently reported beneficial effect of magnesium therapy during spinal cord ischemia.