DISTRIBUTION ALONG RAT NEPHRON OF 3 ENZYMES OF GLUCONEOGENESIS IN ACIDOSIS AND STARVATION
DISTRIBUTION ALONG RAT NEPHRON OF 3 ENZYMES OF GLUCONEOGENESIS IN ACIDOSIS AND STARVATION
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DOI：
10.1152/ajprenal.1978.235.3.f246
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发表时间：
1978-01-01
影响因子：
--
通讯作者：
LOWRY, OH
中科院分区：
文献类型：
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作者：
BURCH, HB;NARINS, RG;LOWRY, OH
设计或修改了方法，使得可以测量单个肾单位的 7 个限定部分以及从大鼠肾脏冻干切片机切片中解剖的细肢和乳头区域的斑块中的磷酸烯醇丙酮酸羧激酶、果糖 - 1,6 - 双磷酸酶和葡萄糖 - 6 - 磷酸酶。所有 3 种酶基本上局限于近端小管。在正常肾脏中，近曲小管中的水平最高。葡萄糖-6-磷酸酶在回旋段的早期部分比在直段的后期部分高20倍。除 1 个例外，在酸中毒时，仅磷酸烯醇丙酮酸羧激酶增加（近曲段增加 4 倍，但直段减少得多）。饥饿时，近端直小管中磷酸烯醇式丙酮酸羧激酶的升高程度与酸中毒时的升高程度相同，但在曲曲部分中则没有那么多，而近端小管的两个部分中的葡萄糖-6-磷酸酶均适度升高，而果糖二磷酸酶仅在直管中升高，尤其是早期段。在近曲小管中，氨生成可以伴随糖异生，但在直段中则不然。
Methods were devised or modified which made it possible to measure phosphoenolpyruvate carboxykinase, fructose-1,6-bisphosphatase and glucose-6-phosphatase in 7 defined parts of single nephrons and in patches from thin limb and papilla areas dissected from freeze-dried microtome sections of rat kidney. All 3 enzymes were essentially confined to the proximal tubule. In normal kidneys, the levels were highest in the proximal convoluted tubule. Glucose-6-phosphatase was 20 times higher in the early part of the convoluted segment than in the late part of the straight segment. With 1 exception, in acidosis, only phosphoenolpyruvate carboxykinase increased (4-fold in the proximal convoluted segment but much less in the straight portion). In starvation, phosphoenolpyruvate carboxykinase increased about as much as in acidosis in the proximal straight tubule, but not as much in convoluted portions, whereas glucose-6-phosphatase rose modestly in both parts of the proximal tubule and fructose bisphosphatase rose only in the straight tubule, especially the early segment. Ammoniagenesis can accompany gluconeogenesis in the proximal convoluted tubule but not in the straight segment.