QUANTITATIVE RELATIONSHIP BETWEEN BRAIN TEMPERATURE AND ENERGY-UTILIZATION RATE MEASURED IN-VIVO USING P-31 AND H-1 MAGNETIC-RESONANCE SPECTROSCOPY

被引：121

作者：

LAPTOOK, AR

CORBETT, RJT

STERETT, R

GARCIA, D

TOLLEFSBOL, G

机构：

[1] UNIV TEXAS,SW MED CTR,DEPT RADIOL,DALLAS,TX 75235

[2] UNIV MED CTR SO NEVADA,DEPT PEDIAT CRIT CARE,LAS VEGAS,NV

来源：

PEDIATRIC RESEARCH | 1995年 / 38卷 / 06期

关键词：

D O I：

10.1203/00006450-199512000-00015

中图分类号：

R72 [儿科学];

学科分类号：

100202 ;

摘要：

In neonatal and adult animals, modest reduction in brain temperature (2-3 degrees C) during ischemia and hypoxia-ischemia provides partial or complete neuroprotection. One potential mechanism for this effect is a decrease in brain energy utilization rate with consequent preservation of brain ATP, as occurs with profound hypothermia, To determine the extent to which modest hypothermia is associated with a decrease in brain energy utilization rate, in vivo P-31 and H-1 magnetic resonance spectroscopy (MRS) was used to measure the rate of change in brain concentration of phosphocreatine, nucleoside triphosphate, and lactate after complete ischemia induced by cardiac arrest in 11 piglets (8-16 d). Preischemia metabolite concentrations and MRS-determined rate constants were used to calculate the initial flux of high energy phosphate equivalents (d[similar to P]/dt, brain energy utilization rate). Baseline physiologic and MRS measurements were obtained at 38.2 degrees C and repeated after brain temperature was adjusted between 28 and 41 degrees C. This was followed by measurement of d[similar to P]/dt during complete ischemia at 1-2 degrees C increments within this temperature range, Adjusting brain temperature did not alter any systemic variable except for heart rate which directly correlated with brain temperature (r = 0.95, p < 0.001). Before ischemia brain temperature inversely correlated with phosphocreatine (r = -0.89, p < 0.001), and reflected changes in the phosphocreatine-ATP equilibrium, because brain temperature inversely correlated with intracellular pH (r = -0.77, p = 0.005). Brain temperature and d[similar to P]/dt were directly correlated and described by a linear relationship (slope = 0.61, intercept = -12, r = 0.92, p < 0.001). A reduction in brain temperature from normothermic values of 38.2 degrees C was associated with a decline in d[similar to P]/dt of 5.3% per 1 degrees C, and therefore decreases in d[similar to P]/dt during modest hypothermia represent a potential mechanism contributing to neuroprotection.

引用

页码：919 / 925

页数：7

共 30 条

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