The effect of reducing proximal tubular fluid delivery on the rate of filtration of single nephrons
| Autor: | G. Favret, Edda Federico, G. Romano, Ettore Bartoli |
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| Rok vydání: | 1998 |
| Předmět: |
Male
medicine.medical_specialty Endocrinology Diabetes and Metabolism Distal tubule Tubular fluid Urology Renal function Nephron law.invention Kidney Tubules Proximal Endocrinology law medicine Animals Rats Wistar Filtration urogenital system Chemistry Nephrons Body Fluids Rats medicine.anatomical_structure Loop of Henle Macula densa Proximal tubule Glomerular Filtration Rate |
| Zdroj: | Journal of endocrinological investigation. 21(4) |
| ISSN: | 0391-4097 |
| Popis: | The rate of delivery of tubular fluid from the proximal tubule (PT) is thought to reset nephron filtration rate (SNGFR). In micropuncture experiments in rats we tested this hypothesis by reducing the efflux from the PT by simultaneously "double collecting" (DC) tubular fluid from the early distal tubule (DT) and from the last convolution of the PT of the same nephrons. SNGFR measured by total collection of tubular fluid was 34 +/- 3 nl/min at the DT and 34 +/- 3 nl/min at the PT (p0.97, n = 42). The simultaneous collection from proximal and distal sampling site was performed between these two paired measurements. It yielded an average SNGFR of 40 +/- 3 nl/min (p0.02). This may be due to the collection, at the distal site, of the extra amount of inulin stored between distal and proximal pipette, prior to starting the aspiration of tubular fluid. Since this error would decrease in longer collections, the difference in SNGFR between single and double collections was plotted against the duration of collections. In fact it was negatively correlated with the sampling time (p0.01), indicating no difference in SNGFRs for collections4 minutes. Reduction and complete interruption of the delivery of native proximal tubular fluid to the Macula Densa does not seem to influence the measurement of SNGFR. Filtration rate is not significantly different when measured within few minutes at the DT and PT of the same nephrons. |
| Databáze: | OpenAIRE |
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