Simpson D P, Hecker J
Am J Physiol. 1979 Aug;237(2):F93-9. doi: 10.1152/ajprenal.1979.237.2.F93.
Tissue slices prepared from renal cortex of littermate dogs with chronic metabolic acidosis or alkalosis were incubated in media with or without arsenite and containing 1 mM L-[14C]glutamine or [1,5-14C]citrate. The presence of arsenite increased the concentration of alpha-ketoglutarate in slices by 5--20 times the values found without this inhibitor. alpha-Ketoglutarate concentrations in acidotic slices were 40% or more greater than those in alkalotic ones when arsenited was present. 14C incorporation into alpha-ketoglutarate was also increased manyfold by arsenite with either labeled glutamine or citrate as substrate. 14CO2 production from labeled glutamine by over 90% and from labeled citrate by over 75%; the difference between 14CO2 production by acidotic and alkalotic slices was greatly reduced or eliminated by arsenite. These results suggest that in chronic metabolic acidosis metabolism of both glutamine and citrate is stimulated at a site or sites preceding formation of alpha-ketoglutarate.
从患有慢性代谢性酸中毒或碱中毒的同窝幼犬肾皮质制备的组织切片,在含有或不含亚砷酸盐且含有1 mM L-[¹⁴C]谷氨酰胺或[1,5-¹⁴C]柠檬酸盐的培养基中孵育。亚砷酸盐的存在使切片中α-酮戊二酸的浓度增加到无此抑制剂时所测值的5至20倍。当存在亚砷酸盐时,酸中毒切片中α-酮戊二酸的浓度比碱中毒切片中的浓度高40%或更多。以标记的谷氨酰胺或柠檬酸盐为底物时,亚砷酸盐也使¹⁴C掺入α-酮戊二酸的量增加了许多倍。标记的谷氨酰胺产生¹⁴CO₂的量增加了90%以上,标记的柠檬酸盐产生¹⁴CO₂的量增加了75%以上;亚砷酸盐极大地减少或消除了酸中毒和碱中毒切片之间¹⁴CO₂产生量的差异。这些结果表明,在慢性代谢性酸中毒中,谷氨酰胺和柠檬酸盐的代谢在α-酮戊二酸形成之前的一个或多个位点受到刺激。