GLUCOSE, GLYCOGEN AND AEROBIC GLYCOLYSIS OF ISOLATED CEREBRAL TISSUES
GLUCOSE, GLYCOGEN AND AEROBIC GLYCOLYSIS OF ISOLATED CEREBRAL TISSUES
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DOI：
10.1042/bj0630250
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发表时间：
1956-01-01
影响因子：
4.1
通讯作者：
TRESIZE, MA
中科院分区：
文献类型：
--
作者：
MCILWAIN, H;TRESIZE, MA
脑组织葡萄糖在切除后迅速下降，在葡萄糖盐水中呼吸后恢复；组织中的水平仍然低于生理盐水的水平。组织中的糖原也在切除时迅速丢失，在葡萄糖盐水中呼吸1小时后恢复了一半。一般的体内抑制剂在切除时保留了大量的糖原，但在37度时开始呼吸时仍会发生糖原丢失。2.5和10毫米葡萄糖的再合成相似，但1毫米葡萄糖的再合成较少。再合成后，排除氧气后，糖原迅速下降，但胰岛素和短暂电脉冲对糖原水平几乎没有影响。在体外呼吸条件下，组织中乳酸含量在死后大幅增加，但降至与体内相似的水平，但仍高于生理盐水。当电脉冲作用于组织时，葡萄糖在几秒钟内开始转化为乳酸盐。在最初的20或30秒内，转化速度为400摩尔/克/小时，但在大约40秒的脉冲后减慢。如果脉搏停止，而乳酸tissue仍在增加，增加会持续几秒钟。在对组织施加脉冲时，乳酸盐和无机磷酸盐的最大瞬时形成速率是相似的，并且也接近与观察到的呼吸增加可能相关的不稳定磷酸盐的形成速率。在葡萄糖或磷酸盐被消耗殆尽之前，持续脉冲的乳酸形成就下降了。最初对兴奋的瞬间糖酵解反应在很大程度上被随后持续的呼吸增加所取代。
The glucose of cere-bral tissues fell rapidly on excision, but was restored when the tissue respired in glucose saline; the level in the tissue remained below that of the saline. The glycogen of the tissue, also rapidly lost on excision, was about half-restored after respiration for 1 hour in glucose saline. General depressants in vivo preserved much of the glycogen from loss on excision, but loss nevertheless occurred on beginning respiration at 37[degree]. Resynthesis was similar in 2.5 and in 10 mm glucose but less in 1 mm. After resynthesis, glycogen fell promptly when O2 was ex-cluded, but insulin and brief application of electrical pulses had little if any effect on glycogen level. The lactate of the tissue which had greatly increased post mortem, on respiration in vitro fell to levels akin to those in vivo, but remained greater than in saline. When electrical pulses were applied to the tissue, glucose began within a few seconds to be converted into lactate. Conversion was at the rate of 400 umoles of lactate/g/hour for the first 20 or 30 seconds, but slowed after about 40 seconds of pulses. If pulses were stopped while the tis-sue lactate was still increasing, the increase continued for some seconds. The maximal transitory rates of formation of lactate and of inorganic phosphate on applying pulses to the tissue were similar, and were also close to that of the formation of labile phosphates potentially associated with the observed increase in respiration. Lactate forma-tion with continued pulses fell before glucose or phosphates were ex-hausted. An initial momentary glycolytic response to excitation is largely replaced by a subsequent, sustained increase in respiration.