Ishige N, Pitts L H, Berry I, Nishimura M C, James T L
Department of Neurological Surgery, School of Medicine and Pharmacy, University of California, San Francisco.
J Neurosurg. 1988 Jan;68(1):129-36. doi: 10.3171/jns.1988.68.1.0129.
To clarify the effect of hypovolemic hypotension on high-energy phosphate metabolism in head injury, sequential changes in in vivo phosphorus-31 magnetic resonance (31P MR) spectra were compared in 35 rats after impact injury with and without hypotension. Fourteen rats were subjected to hypotension alone (mean arterial blood pressure (MABP) of either 40 or 30 mm Hg for 60 minutes), seven to fluid-percussion impact injury (4 to 5 atm) alone, and 14 to impact injury and hypotension (MABP of 40 to 30 mm Hg). Impact injury alone caused a transient decrease in the phosphocreatine (PCr) level and an increase in the inorganic phosphate (Pi) value. While hypotension alone produced only small changes on 31P MR spectra, impact injury plus hypotension caused pronounced changes. Impact injury and an MABP of 40 mm Hg caused a 50% decrease in PCr concentration and an approximately twofold increase in Pi level, which were significantly greater than values in rats with impact injury alone. Impact injury and an MABP of 30 mm Hg also caused a significant decrease in adenosine triphosphate value, which was not observed in rats with impact injury alone or with an MABP of 30 mm Hg alone. Decreases in intracellular pH were greater in rats with impact injury and hypotension. After traumatic injury, the brain is extremely vulnerable to hypovolemic hypotension, as reflected in the loss of high-energy phosphates in brain.
为阐明低血容量性低血压对颅脑损伤中高能磷酸代谢的影响，在35只大鼠撞击伤后有或无低血压的情况下，比较了体内磷-31磁共振（31P MR）谱的连续变化。14只大鼠仅接受低血压处理（平均动脉血压（MABP）为40或30 mmHg，持续60分钟），7只仅接受液压冲击伤（4至5个大气压），14只接受冲击伤和低血压处理（MABP为40至30 mmHg）。单纯冲击伤导致磷酸肌酸（PCr）水平短暂下降，无机磷酸盐（Pi）值升高。虽然单纯低血压在31P MR谱上仅产生微小变化，但冲击伤加低血压则导致明显变化。冲击伤和MABP为40 mmHg导致PCr浓度下降50%，Pi水平升高约两倍，这明显大于单纯冲击伤大鼠的值。冲击伤和MABP为30 mmHg也导致三磷酸腺苷值显著下降，这在单纯冲击伤大鼠或仅MABP为30 mmHg的大鼠中未观察到。冲击伤合并低血压的大鼠细胞内pH值下降更大。创伤后，大脑极易受到低血容量性低血压的影响，这反映在大脑中高能磷酸盐的丢失上。
