Effects of formate and oxalate on volume absorption in rat proximal tubule.
Effects of formate and oxalate on volume absorption in rat proximal tubule.
复制标题
甲酸盐和草酸盐对大鼠近曲小管容量吸收的影响。
DOI：
10.1152/ajprenal.1992.263.1.f37
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发表时间：
1992
期刊：
影响因子：
--
通讯作者：
Aronson,PS
中科院分区：
文献类型：
--
作者：
Wang,T;Giebisch,G;Aronson,PS
我们观察了甲酸盐和草酸盐对大鼠在体近曲小管液体吸收率的影响。近端小管用高氯、低HCO3-Ringer液(pH 6.7)微灌流，管周毛细血管用标准Ringer液(pH 7.4)灌流，模拟近端小管晚期的情况。JV是在这些条件下通过管腔吸收氯化钠的量度，由管腔[~3H]菊糖的变化计算出来。向管腔灌流液中添加生理范围(500微米)的甲酸盐可使JV增加45%；向管腔和毛细血管灌流液中添加500微米甲酸盐可使JV增加57%。同样，向管腔灌流液中添加生理范围(5微米)的草酸盐可使JV增加37%；向管腔和毛细血管灌流液中添加5微米草酸盐可使JV增加57%。管腔和毛细血管内灌流的甲酸盐和草酸盐的刺激作用不是相加的。向灌流液中加入4，4‘-二异硫氰基二苯乙烯-2，2’-二磺酸(DIDS，0.1 mM)对不添加甲酸盐和草酸盐的基础JV无影响，但完全消除甲酸盐和草酸盐引起的JV增加。向毛细血管灌流液中加入氯离子通道阻滞剂二苯胺-2-羧酸盐(DPC，0.2 mM)对基础JV无影响，但完全消除甲酸盐和草酸盐引起的JV增加。
We examined the effects of formate and oxalate on the rate of fluid absorption (Jv) in the rat proximal convoluted tubule in situ. Proximal tubules were microperfused with a high-Cl-, low-HCO3- Ringer solution (pH 6.7), and the peritubular capillaries were perfused with a standard Ringer solution (pH 7.4), simulating conditions in the late proximal tubule. Jv, a measure of transtubular NaCl absorption under these conditions, was calculated from the change in luminal [3H]inulin. Addition of formate in the physiological range (500 microM) to the luminal perfusate increased Jv by 45%; addition of 500 microM formate to both luminal and capillary perfusates increased Jv by 57%. Similarly, addition of oxalate in the physiological range (5 microM) to the luminal perfusate increased Jv by 37%; addition of 5 microM oxalate to both luminal and capillary perfusates increased Jv by 57%. The stimulatory effects of formate and oxalate perfused in the lumen and capillaries were not additive. Addition of 4,4'-diisothiocyanostilbene-2,2'-disulfonate (DIDS, 0.1 mM) to the luminal perfusate had no effect on baseline Jv measured in the absence of added formate and oxalate but completely abolished the increment in Jv induced by formate and oxalate. Addition of the Cl(-)-channel blocker diphenylamine-2-carboxylate (DPC, 0.2 mM) to the capillary perfusate had no effect on baseline Jv but completely abolished the increment in Jv induced by formate and oxalate.(ABSTRACT TRUNCATED AT 250 WORDS)