Luke R G
J Clin Invest. 1974 Dec;54(6):1329-36. doi: 10.1172/JCI107879.
These experiments were aimed at investigating renal behavior towards chloride, as distinct from sodium, during dietary deprivation of these ions in adrenalectomized rats. Adrenalectomized and shamoperated control rats were maintained on saline for 3 wk, then chloride conservation during a very low chloride intake was assessed both with an abundant sodium intake (as buffered sodium phosphate in the drinking water) and after subsequent withdrawal of sodium. When sodium intake was high, there was no difference in chloride conservation between adrenalectomized and control animals, and sodium balance and weight were maintained similarly in both groups. At the same time, both experimental and control rats developed significant hypokalemia and elevation of the plasma bicarbonate levels as compared to other control rats ingesting a normal diet. In another group of adrenalectomized rats sodium phosphate was withdrawn, after normal chloride conservation was observed, and the low-salt diet continued. Negative sodium balance developed and was associated with a negative chloride balance, whereas sham-operated rats continued to conserve sodium and chloride. In further studies during polyuria, both adrenalectomized and control rats developed urinary chloride concentrations of less than 1 meq/liter. Thus adrenalectomized rats can maintain chloride balance on a low chloride, high sodium intake, in contrast to their inability to conserve sodium on a low-sodium intake. It is concluded that renal tubular reabsorption of chloride in adrenalectomized rats is adequate to establish and maintain very low urinary chloride concentrations, which may imply active chloride transport in the papillary collecting duct despite the absence of adrenocortical hormone. In addition, the typical renal response to chloride deprivation, enhanced loss of potassium and accelerated reabsorption of bicarbonate, is not dependent on adrenocortical hormones.
这些实验旨在研究肾上腺切除大鼠在饮食中缺乏这些离子时，肾脏对氯离子（与钠离子不同）的处理情况。将肾上腺切除和假手术对照大鼠用生理盐水维持3周，然后在极低的氯化物摄入量下评估氯化物的保留情况，分别在高钠摄入量（作为饮用水中的缓冲磷酸钠）时以及随后撤去钠之后进行评估。当钠摄入量高时，肾上腺切除动物和对照动物在氯化物保留方面没有差异，两组的钠平衡和体重维持情况相似。同时，与摄入正常饮食的其他对照大鼠相比，实验大鼠和对照大鼠均出现了明显的低钾血症和血浆碳酸氢盐水平升高。在另一组肾上腺切除大鼠中，在观察到正常的氯化物保留后撤去磷酸钠，并继续低钠饮食。出现了负钠平衡，并伴有负氯平衡，而假手术大鼠继续保留钠和氯。在多尿期的进一步研究中，肾上腺切除大鼠和对照大鼠的尿氯浓度均低于1毫当量/升。因此，与低钠摄入时无法保留钠相反，肾上腺切除大鼠在低氯、高钠摄入时能够维持氯平衡。结论是，肾上腺切除大鼠肾小管对氯的重吸收足以建立和维持极低的尿氯浓度，这可能意味着尽管没有肾上腺皮质激素，乳头集合管中仍存在氯的主动转运。此外，对氯缺乏的典型肾脏反应，即钾的丢失增加和碳酸氢盐重吸收加速，并不依赖于肾上腺皮质激素。
