[Histopathology of the kidney in pseudo-Bartter's Syndrome induced by chronic abuse of diuretics (author's transl)].

A 38-year-old female patient developed a Pseudo-Bartter's-Syndrome with hypokalemic alkalosis, hyponatremia and hyperrenism as the result of the abuse of diuretics (furosemide, spironolactone, thiabutacide) for a period of more than 10 years. The needle biopsy specimen from the kidney showed a hyperplasia of the juxtaglomerular apparatus and of the mesangium cells as the morphologic basis of hyperrenism, a focal vacuolisation of the proximal tubular epithelium and a focal atrophy of the distal tubules. The pathogenesis of the tubular alterations and their possible relation to hypokalemia, hypoxemia or drug-toxicity is discussed, a satisfactory interpretation, however, cannot be given. The encroachment of proximal tubular epithelium on the parietal layer of Bowman's capsule is another striking pathoanatomical finding, and considered a compensatory mechanism under the continuous loss of water.