LACTATE PRODUCTION IN ISOLATED SEGMENTS OF THE RAT NEPHRON
LACTATE PRODUCTION IN ISOLATED SEGMENTS OF THE RAT NEPHRON
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DOI：
10.1152/ajprenal.1985.248.4.f522
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发表时间：
1985-01-01
影响因子：
--
通讯作者：
BURG, M
中科院分区：
文献类型：
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作者：
BAGNASCO, S;GOOD, D;BURG, M
直接在大鼠肾单位的各个节段中测量乳酸产生。将小管切开，然后在体外以葡萄糖作为唯一代谢底物孵育。每个片段与抗霉素A（一种氧化代谢抑制剂）一起孵育。无论是否使用抗霉素A，近端小管均不产生乳酸。远端节段均产生乳酸。在没有抗霉素A的情况下，乳酸盐产生的速率范围为0.4-0.9 pmol/min。mm，在所有远端节段中，除了一个，内髓集合管，其以2.8 pmol/min的显著更高的速率产生乳酸。抗霉素A显著增加了所有远端节段的乳酸产生。在髓质粗的升支（1400%）和皮质（798%）和外髓集合管（357%）中增加最多。皮质厚的升支（98%）和远曲小管（98%）的增量较小，内髓集合管（28%）的增量最小。显然，乳酸的产生仅发生在肾单位的远端节段;在缺氧条件下，这些节段中的厌氧糖酵解明显产生大量ATP。
Lactate production was measured directly in individual segments of the rat nephron. Tubules were dissected and then incubated in vitro with glucose as the only metabolic substrate. Each segment was incubated with and without antimycin A, an inhibitor of oxidative metabolism. Proximal tubules produced no lactate with or without antimycin A. The distal segments all produced lactate. The rate of lactate production without antimycin A ranged from 0.4-0.9 pmol/min .cntdot. mm in all distal segments except one, the inner medullary collecting duct, which produced lactate at the significantly higher rate of 2.8 pmol/min .cntdot. mm. Antimycin A increased lactate production significantly in all of the distal segments. The increase was largest in medullary thick ascending limbs (1400%) and cortical (798%) and outer medullary collecting ducts (357%). Increments were smaller in cortical thick ascending limbs (98%) and distal convoluted tubules (98%) and least in the inner medullary collecting ducts (28%). Apparently, lactate production occurs only in distal segments of the nephron; under anoxic conditions significant amounts of ATP evidently are produced by anaerobic glycolysis in these segments.