Saito T
Department of Physiology, Faculty of Veterinary Medicine, Hokkaido University, Sapporo, Japan.
Brain Res. 1990 Dec 10;535(2):205-13. doi: 10.1016/0006-8993(90)91602-d.
Optical absorbance change was measured by reflectance spectrophotometry in the olfactory cortex slice prepared from the rat brain. Optical absorbance of the piriform area of the slice was increased by perifusion with an anoxic (N2-gassed) solution. Components of the absorbance spectrum recorded from the slice in anoxia corresponded to that of cytochromes (cyt) aa3 and c + c1, but did not to that of cyt c. Reduction of cytochromes in anoxia coincided with decrease in the amplitude of the presynaptic potential and a slower negative wave (N-wave). The reduced state of cytochromes switched to an oxidized state when a well-oxygenated solution was reintroduced. An almost complete recovery of redox state coincided with full recovery of the evoked potential. A metabolic inhibitor, 2-deoxy-D-glucose (2DG) (10 mM) or iodoacetic acid (IAA) (3 mM) caused little or slight oxidation of cytochromes, but significantly decreased the amplitude of evoked potentials. Marked oxidation of cytochromes was observed only by perifusion with a solution containing 2 DG (10 mM) and IAA (3 mM). The rate of oxygen uptake was significantly lowered by these metabolic inhibitors. When the slice was perifused with a solution containing fluoroacetate (1 or 10 mM), a selective inhibitor of glial metabolism, cytochromes shifted to oxidized levels. The amplitude of evoked potentials tended to decline by a low dose (1 mM), and significantly decreased by a high dose (10 mM) of fluoroacetate. Oxygen consumption of the slice was dose-relatedly lowered by fluoroacetate.(ABSTRACT TRUNCATED AT 250 WORDS)
通过反射分光光度法测量从大鼠脑制备的嗅觉皮质切片中的光吸收变化。用缺氧（氮气饱和）溶液灌流可增加切片梨状区的光吸收。缺氧时从切片记录的吸收光谱成分与细胞色素（cyt）aa3和c + c1的光谱成分相对应，但与cyt c的光谱成分不对应。缺氧时细胞色素的还原与突触前电位幅度的降低和较慢的负波（N波）同时出现。当重新引入充分氧合的溶液时，细胞色素的还原状态转变为氧化状态。氧化还原状态几乎完全恢复与诱发电位的完全恢复同时发生。代谢抑制剂2-脱氧-D-葡萄糖（2DG）（10 mM）或碘乙酸（IAA）（3 mM）引起细胞色素的少量或轻微氧化，但显著降低诱发电位的幅度。仅通过用含有2DG（10 mM）和IAA（3 mM）的溶液灌流观察到细胞色素的明显氧化。这些代谢抑制剂显著降低了氧摄取率。当用含有氟乙酸盐（1或10 mM）（一种胶质细胞代谢的选择性抑制剂）的溶液灌流切片时，细胞色素转变为氧化水平。低剂量（1 mM）氟乙酸盐使诱发电位幅度趋于下降，高剂量（10 mM）则使其显著降低。氟乙酸盐使切片的氧消耗呈剂量依赖性降低。（摘要截短于250字）
