Kantariya V A, Lebedev A A
Pflugers Arch. 1975 Oct 16;360(1):81-9. doi: 10.1007/BF00584328.
Electrophysiological micropuncture techniques were used to study the effect of certain diuretics on transtubular transport of electrolytes in the rat kidney. The mercurial diuretic novurite caused a reduction of active sodium transport in the proximal tubule, measured by short-circuit current and increased permeability of the tubular wall to ions which led to a considerable drop in transtubular potential and transepithelial resistance. Ethacrynic acid decreased the short-circuit current in the proximal tubule, without changing the permeability characteristics of the nephron. Xanthine diuretic euphylline did not reduce the short-circuit current in the proximal segment of the nephron; however, it increased the transepithelial potential of the renal tubule. In the distal tubule, euphylline and ethacrynic acid increased the difference in transtubular potential, whereas novurite reduced the transtubular potential. An increase in the electrical gradient of the distal tubule as a result of euphylline and ethacrynic acid action may be responsible for increasing potassium excretion. A decrease of the transtubular potential in the potassium excretion under mercurial diuretic action. The reduction of tubular reabsorption as a result of diuretic action is due to drug effect on different levels of the transtubular-ion transport system.
采用电生理微穿刺技术研究了某些利尿剂对大鼠肾脏电解质跨肾小管转运的影响。汞利尿剂诺呋利特可使近端小管的主动钠转运减少，这通过短路电流来衡量，并且会增加肾小管壁对离子的通透性，从而导致跨肾小管电位和跨上皮电阻显著下降。依他尼酸可降低近端小管的短路电流，但不改变肾单位的通透性特征。黄嘌呤利尿剂氨茶碱不会降低肾单位近端节段的短路电流；然而，它会增加肾小管的跨上皮电位。在远端小管，氨茶碱和依他尼酸会增加跨肾小管电位差，而诺呋利特会降低跨肾小管电位。氨茶碱和依他尼酸作用导致远端小管电位梯度增加，这可能是钾排泄增加的原因。汞利尿剂作用下钾排泄时跨肾小管电位降低。利尿剂作用导致肾小管重吸收减少是由于药物对跨肾小管离子转运系统不同水平的影响。
