Hope P L, Cady E B, Chu A, Delpy D T, Gardiner R M, Reynolds E O
J Neurochem. 1987 Jul;49(1):75-82. doi: 10.1111/j.1471-4159.1987.tb03396.x.
Brain metabolism and intracellular pH were studied during and after episodes of ischaemia and hypoxia-ischaemia in lambs anaesthetised with sodium pentobarbitone. 31P and 1H magnetic resonance spectroscopy methods were used to monitor brain pHi and brain concentrations of Pi, phosphocreatine (PCr), beta--nucleoside triphosphate (beta NTP), and lactate. Simultaneous measurements were made of cerebral blood flow and cerebral oxygen and glucose consumption. Cerebral ischaemia sufficient to reduce oxygen delivery to 75% of control values was associated with a fall in brain pHi and increase in brain Pi. Progressively severe hypoxia-ischaemia was associated with a progressive fall in brain pHi, PCr, and beta NTP and increase in brain Pi. In two animals the increase in brain lactate during hypoxia-ischaemia measured by 1H nuclear magnetic resonance (NMR) could be quantitatively accounted for by the increased net uptake of glucose by the brain in relation to oxygen, but was insufficient to account for the concomitant acidosis according to previous estimates of brain buffering capacity. In four animals brain pHi, PCr, Pi, and beta NTP had returned to normal 1 h after the hypoxic-ischaemic episode. In one animal brain pHi had reverted to normal at a time when 1H NMR indicated persistent elevation of brain lactate.
在用戊巴比妥钠麻醉的羔羊发生缺血及缺氧缺血期间和之后，对其脑代谢和细胞内pH值进行了研究。采用³¹P和¹H磁共振波谱法监测脑内pH值以及无机磷（Pi）、磷酸肌酸（PCr）、β - 核苷三磷酸（β NTP）和乳酸的脑内浓度。同时测量脑血流量以及脑氧耗量和葡萄糖消耗量。足以将氧输送量降低至对照值75%的脑缺血与脑内pH值下降及脑内Pi增加相关。逐渐加重的缺氧缺血与脑内pH值、PCr和β NTP逐渐下降以及脑内Pi增加相关。在两只动物中，通过¹H核磁共振（NMR）测量的缺氧缺血期间脑内乳酸增加量，可根据脑相对于氧的葡萄糖净摄取增加量进行定量解释，但根据先前对脑缓冲能力的估计，这不足以解释伴随的酸中毒。在四只动物中，缺氧缺血发作后1小时，脑内pH值、PCr、Pi和β NTP恢复正常。在一只动物中，当¹H NMR显示脑内乳酸持续升高时，脑内pH值已恢复正常。
