Effect of parathyroid hormone on bicarbonate absorption by proximal tubules in vitro.
Effect of parathyroid hormone on bicarbonate absorption by proximal tubules in vitro.
复制标题
甲状旁腺激素对体外近曲小管吸收碳酸氢盐的影响。
DOI：
10.1152/ajprenal.1979.236.4.f387
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发表时间：
1979
期刊：
影响因子：
--
通讯作者：
M. Burg
中科院分区：
文献类型：
--
作者：
Y. Iino;M. Burg
研究了甲状旁腺激素对兔肾近端小管吸收碳酸氢盐的影响。在近端直小管中，0.05 U/ml甲状旁腺激素引起小管液中稳态碳酸氢盐浓度的显著可逆升高。此外，碳酸氢盐的速率和液体吸收（以更快的流速测量）被激素抑制了大约50%。我们得出结论，甲状旁腺激素直接抑制近端直小管对液体和碳酸氢盐的吸收，导致小管液体中碳酸氢盐浓度的增加，我们认为这种激素的作用有助于肾脏碳酸氢盐排泄的增加，这通常是由激素引起的。在近曲小管中，其他研究者先前已证实甲状旁腺激素对液体和碳酸氢盐吸收的抑制作用大致成比例，因此小管液体中的碳酸氢盐浓度几乎没有变化。在本研究中，我们一致发现0.05 U/ml的激素不影响近曲小管液中碳酸氢盐的稳态浓度，而5 U/ml的激素只引起小管液碳酸氢盐浓度的模糊增加。
The effect of parathyroid hormone on bicarbonate absorption was tested in rabbit proximal renal tubules perfused in vitro. In proximal straight tubules 0.05 U/ml of parathyroid hormone caused a large and reversible increase in the steady-state bicarbonate concentration in tubule fluid. Further, the rates of bicarbonate and fluid absorption (measured at faster flow rates) were inhibited approximately 50% by the hormone. We conclude that parathyroid hormone directly inhibits fluid and bicarbonate absorption by proximal straight tubules, causing an increase in the bicarbonate concentration in the tubule fluid, and we suggest that this action of the hormone contributes to the increase in renal bicarbonate excretion that is generally caused by the hormone. In proximal convoluted tubules, parathyroid hormone was previously demonstrated by other investigators to inhibit fluid and bicarbonate absorption approximately proportionally, so that there was little or no change in the bicarbonate concentration in tubule fluid. In agreement we found in the present studies that 0.05 U/ml of the hormone did not affect the steady-state bicarbonate concentration in proximal convoluted tubule fluid and that 5 U/ml caused only an equivocal increase in tubule fluid bicarbonate concentration.