[Diuretics as factors regulating electrolyte transport through the wall of the kidney tubule]

The effects of furosemide, hydrochlorthiazide, triamteren and mannitol on the intratubular potential, electric resistance of the wall of the proximal and distal renal tubule and also changes in the magnitude of the short-circuited current that give an idea as to the tubular transport of sodium in the proximal section of nephron were explored electrophysiologically on a renal nephron of the rat. Furosemide and hydrochlorthiazide depressed the magnitude of the short-circuited current in the proximal end of nephron and raised the transtubular potential. Hydrochlorthiazide also tended to increase the electric resistance of the renal tubule wall. Triamteren forced down the potential in the proximal end of nephron, as well as the magnitude of the short-circuited current, but did not change the tubular wall resistance. Mannitol drastically reduced the tubular wall resistance and the intratubular potential, without affecting the short-circuited current. A classification of diuretics by the mode of their action on the electric parameters of the nephron is given.