Eknoyan G, Sawa H, Hyde S, Wood J M, Schwartz A, Suki W
J Pharmacol Exp Ther. 1975 Sep;194(3):614-23.
An effect of diuretics on cellular metabolism has been shown. In order to examine further the direct effect of diuretics on renal mitochondria, their effect on isolated cortical (C) and outer medullary (OM) mitochondrial respiration was examined. Oxygen consumption rate (QO2) was measured in a Gilson oxygraph utilizing either glutamate-malate or succinate as substrate. QO2, expressed in nanoatoms of O2 per milligram of protein per minute, was always higher in C than OM: 140.7 +/- 2.8 VS. 121.2 +/- 2.4 (P less than 0.001) with glutamate-malate and 181.1 +/- 6.3 vs. 129.7 +/- 5.2 (P less than 0.001) with succinate. A dose-response curve was constructed for each of the following: sodium ethacrynate, furosemide, chlorothiazide, acetazolamide and chlormerodrin. All diuretics inhibited C and OM equally. The 50% inhibitory molar concentration for EA was 6.2 times 10(-4); for furosemide 1.5 times 10(-3); for chlorothiazide 8.1 times 10(-3); for acetazolamide 10.8 times 10(-3); and for chlomerodrin 3.1 times 10(-5). Neither cysteine nor dithiothreitol inhibited the effect of EA. The effect of chlormerodrin was abolished by cysteine. These results demonstrate that while a difference exists between C and OM mitochondria during control studies, each of the diuretics examined exerted an equal inhibitory effect on mitochondrial respiration from both C and OM. Mercurials are the most potent inhibitors and presumably exert their effect by reacting with sulfhydryl groups. They are followed in potency by ethacrynic acid, furosemide, chlorothiazide and acetazolamide.
利尿剂对细胞代谢的作用已得到证实。为了进一步研究利尿剂对肾线粒体的直接作用，检测了它们对分离的皮质（C）和外髓（OM）线粒体呼吸的影响。在吉尔森氧电极中，以谷氨酸 - 苹果酸或琥珀酸为底物测量氧消耗率（QO2）。QO2以每分钟每毫克蛋白质消耗的氧的纳摩尔数表示，C中的QO2总是高于OM：以谷氨酸 - 苹果酸为底物时为140.7±2.8对121.2±2.4（P＜0.001），以琥珀酸为底物时为181.1±6.3对129.7±5.2（P＜0.001）。为以下每种利尿剂构建了剂量 - 反应曲线：依他尼酸钠、呋塞米、氯噻嗪、乙酰唑胺和氯汞君。所有利尿剂对C和OM的抑制作用相同。依他尼酸的50%抑制摩尔浓度为6.2×10⁻⁴；呋塞米为1.5×10⁻³；氯噻嗪为8.1×10⁻³；乙酰唑胺为10.8×10⁻³；氯汞君为3.1×10⁻⁵。半胱氨酸和二硫苏糖醇均未抑制依他尼酸的作用。氯汞君的作用被半胱氨酸消除。这些结果表明，虽然在对照研究中C和OM线粒体之间存在差异，但所检测的每种利尿剂对C和OM的线粒体呼吸均产生同等的抑制作用。汞剂是最有效的抑制剂，推测其作用是通过与巯基反应实现的。其效力依次为依他尼酸、呋塞米、氯噻嗪和乙酰唑胺。
