Macropuncture study of polycystic disease in adult human kidneys

Macropuncture study of polycystic disease in adult human kidneys. Solute composition, volume, and hydrostatic pressure were measured in cysts from eight patients with the adult form of polycystic kidney disease (PCKD). Five azotemic patients had elective nephrectomies in preparation for renal transplantation, two nonazotemic patients had their polycystic kidneys removed several weeks after a successful renal allograft, and one nonazotemic cadaver was inadvertently nephrectomized as a potential kidney donor. In all patients, the pattern of solute concentrations in cyst fluid segregated into two principal groups: Proximal cysts had sodium, potassium, chloride, hydrogen ion, creatinine, and urea values virtually equal to their respective sera, whereas distal cysts had sodium and chloride concentrations lower and potassium, hydrogen ion, creatinine, and urea concentrations greater than serum. In the two subjects who received renal allografts and were not azotemic, creatinine and urea concentrations in the proximal cysts reflected nonazotemic values, indicating redistribution of these solutes across proximal cyst walls after the extracellular fluid was normalized. By contrast, distal cysts maintained steep concentration gradients for creatinine and urea. Transmural hydrostatic pressures were similar in proximal and distal cysts and were not different from normal intratubular pressures. These studies provide strong support for the view that cysts are massively enlarged segments of nephrons and collecting tubules that qualitatively maintain their basic solute transport functions throughout the life of the patient. Etude de la maladie polykystique par ponctions de reins d'humains adultes. La composition en substances dissoutes, le volume et al pression hydrostatique ont ete mesures dans les kystes de huit malades atteints de la forme adulte de la maladie polykystique (PCKD). Cinq malades atteints d'insuffisance renale ont subi des nephrectomies preparatoires a la transplantation renale, deux malades non azotemiques ont eu l'ablation des reins polykystiques quelques semaines apres une greffe renale reussie et un prelevement a ete fait sur un cadavre considere comme un donneur potentiel. Chez tous les sujets les profils des concentrations de substances dissoutes dans le liquide des kystes se repartissent en deux categories principales: les kystes proximaux ont des valeurs de sodium, potassium, chloride, hydrogene, creatinine, et uree pratiquement egales a leurs plasma respectifs, alors que les kystes distaux ont des concentrations de sodium et chloride plus faibles et des concentrations de potassium, hydrogene, creatinine, et uree plus elevees que celles du plasma. Chez deux sujets qui avaient recu des allogreffes et n'etaient pas azotemiques les concentrations de creatinine et de l'uree dans les kystes proximaux refletaient les valeurs non azotemiques, ce qui indique une redistribution de ces substances dissoutes a travers la paroi des kystes proximaux apres que le liquide extracellulaire ait ete normalise. Les kystes distaux, au contraire, maintiennent une difference de concentration importante pour la creatinine et l'uree. Les pressions hydrostatiques transmurales sont semblables dans les kystes proximaux et distaux et ne sont pas differentes des pressions intra-tubulaires normales. Ces etudes apportent un argument important en faveur de l'hypothese selon laquelle les kystes sont des segments de nephrons tres grossis qui conservent qualitativement leurs fonctions elementaires de transport tout au long de la vie du malade.