ISSN:1660-8151    

DOI:10.1159/000179313

出版商:S. Karger AG    

年代:1964

数据来源: Karger

摘要:

Renal excretion of hydrogen ion has been measured in six patients recovering from acute oliguric renal failure. Despite extracellular acidosis the majority of patients were unable to lower their urine pH to the values achieved by acidotic normal subjects. This defect was not as marked as is usually seen in patients with renal tubular acidosis.Ammonium excretion was markedly reduced in all patients. Endogenous creatinine clearance was also reduced, the reduction in ammonium excretion being proportional to the reduction in creatinine clearance. As this relationship is seen in other forms of renal disease, even in the absence of signs of tubular dysfunction, it cannot be concluded that a low ammonium excretion in acute oliguric renal failure is the direct result of structural damage to the renal tubular epithelium.

ISSN:1660-8151    

DOI:10.1159/000179314

出版商:S. Karger AG    

年代:1964

数据来源: Karger

摘要:

1. Une amylose rénale est induite chez des hamsters dorés par inoculation de Leishmania Donovani. Vingt-trois animaux ont été infectés et leurs reins ont été examinés au cours de cinq series de prélèvements pratiques de la troisième à la treizième semaine après l’infection. 2. L’examen au microscope optique a montré cinq amyloses débutantes chez les dix animaux sacrifiés à la douzième et à la treizième semaine. 3. L’examen au microscope électronique a été fait sur les reins de huit hamsters: a) 2 hamsters ayant des reins normaux au microscope optique (9ème semaine); b) 4 hamsters ne montrant, au microscope optique, qu’une hypertrophie modérée des espaces intercapillaires mais sans lésions amyloïdes (12ème et 13ème semaine). c) 2 hamsters ayant une amylose débutante visible au microscope optique (13ème semaine). Les reins de deux animaux de la série «b» ont de très petits dépôts amyloïdes strictement localisés dans les espaces intercapillaires; les reins des animaux de la série «c» ont des dépots amyloïdes à prédominance intercapillaire et quelques dépôts plus diffus dans les parois capillaires périphériques. Ces résultats soulignent le rôle particulier des espaces intercapillaires dans la localisation précoce de l’amylose rénale expérímentale; leur signification est discutée dans le texte. 4. Deux aspects inhabituels de la substance amyloïde sont décrits. Le premier est caractérisé par la presence de nombreuses petites vésicules (300 Å environ) accolées aux fibrilles amyloïdes, le deuxième par la pénétration de fibrilles isolées dans le cytoplasme épithélial. 5. Une hypertrophie modérée des espaces intercapillaires et des excroissances nodulaires de la membrane basale sont retrouvés chez tous les animaux sacrifiés à la 12è

ISSN:1660-8151    

DOI:10.1159/000179316

出版商:S. Karger AG    

年代:1964

数据来源: Karger

摘要:

The results and significance of some recently published micropuncture studies have been discussed. It is apparent that water transport in all segments of the kidney is passive and, at least in the distal tubule and collecting duct, is modified by ADH. Sodium absorption, by contrast, is an active process in all species studied. This ion is actively extruded at the antiluminal surface of both the proximal and distal tubule. In the proximal tubule cell of Necturus there is also evidence of an outwardly directed sodium pump at the luminal membrane. Chloride absorption from the proximal tubule is in the direction of a combined electrochemical potential gradient but in Necturus, at least, there is required active uptake at both cell surfaces to account for the observed intracellular chloride concentration and flux ratios. Potassium absorption in the proximal tubule of rat and Necturus requires an active transport process at the luminal surface despite the fact that net transtubular potassium transport in Necturus approximates that predicted for passive transport. In Necturus, too, the combined electrochemical potential difference across the luminal membrane demands the presence of an inward directed pump at the antiluminal surface of the cell. A model of the proximal tubule cell is thereby derived (Fig. 2). In this figure, active transport processes are depicted with black arrows whose direction denotes the direction of the pump. Unidirectional passive fluxes are shown as white arrows, their relative magnitude being indicated by length. This model differs considerably from others, symmetry of transport of the various ion species being apparent at luminal and antiluminal surfaces of the cell. A coupled sodium-potassium mechanism has not been postulated here since there is no direct evidence for such a phenomenon in the proximal tubule of Necturus kidney. It must be stressed, however, that the accuracy of this model depends entirely on the reported values for intracellular ion concentrations and on the condition that such values reflect free ion activities in cell water. It is hazardous to attempt to make a comparable cell model for the mammalian proximal tubule since potential differences at each cell border, membrane permeabilities, and even intracellular ion activities are not known with certainty in a single species. And certainly, when produced, this model may be quite different from the one evolved for that strange animal, Necturus.

ISSN:1660-8151    

DOI:10.1159/000179317

出版商:S. Karger AG    

年代:1964

数据来源: Karger

ISSN:1660-8151    

DOI:10.1159/000179318

出版商:S. Karger AG    

年代:1964

数据来源: Karger

ISSN:1660-8151    

DOI:10.1159/000179319

出版商:S. Karger AG    

年代:1964

数据来源: Karger

ISSN:1660-8151    

DOI:10.1159/000179320

出版商:S. Karger AG    

年代:1964

数据来源: Karger