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. 1971 Oct;50(10):2191–2203. doi: 10.1172/JCI106714

The relative contributions of reabsorptive rate and redistributed nephron filtration rate to changes in proximal tubular fractional reabsorption during acute saline infusion and aortic constriction in the rat

Ettore Bartoli 1,2, Laurence E Earley 1,2
PMCID: PMC292154  PMID: 5116209

Abstract

The absolute rate of reabsorption by superficial rat proximal tubules was measured by the in situ microperfusion technique under conditions of hydropenia, infusion of saline, and infusion of saline plus aortic constriction sufficient to decrease whole kidney filtration rate below hydropenic levels. Fractional reabsorption was measured in adjacent filtering nephrons by collecting and recollecting tubular fluid from late proximal convolutions during each experimental condition. During hydropenia, the absolute rate of proximal tubular reabsorption averaged 3.56 ±0.60 nl/min per mm and late proximal tubular fractional reabsorption averaged 0.56 ±0.10. From these two measurements and measurements of tubule length to the site of micropuncture, a value for filtration rate was calculated for filtering nephrons. During hydropenia this value averaged 32.9 ±7.1 nl/min. Saline infusion increased sodium excretion to 5.5% of the filtered load as the absolute rate of proximal tubular reabsorption decreased 38% and fractional reabsorption decreased 45%. Calculated superficial nephron filtration rate increased 21% which on the average was identical with the simultaneously measured increase in whole kidney filtration rate. Similar results were obtained in a separate group of animals by the technique of total collection of late proximal tubular fluid. Aortic constriction during saline infusion decreased whole kidney and calculated nephron filtration rate to the same degree and to values lower than those during hydropenia. Fractional reabsorption increased but not to hydropenic values. The persistent natriuresis during aortic constriction was associated with a continued depression of the absolute rate of proximal tubular reabsorption which was sufficient to maintain an increased delivery of filtrate out of the proximal tubule despite the fall in nephron filtration rate. These results indicate that depressed fractional reabsorption in the proximal tubule during acute saline infusion is due predominantly to a decrease in absolute reabsorptive rate and to a lesser extent to an increase in superficial nephron filtration rate which is proportional to the increase in whole kidney filtration. Continued natriuresis when filtration rate is decreased during saline infusion can be accounted for entirely by the persistent large reduction in the absolute rate of proximal tubular reabsorption.

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Selected References

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  1. Anderson C. F., Sawyer T. K., Cutler R. E. Iothalamate sodium I 125 vs cyanocobalamin Co 57 as a measure of glomerular filtration rate in man. JAMA. 1968 May 20;204(8):653–656. [PubMed] [Google Scholar]
  2. Arrizurieta-Muchnik E. E., Lassiter W. E., Lipham E. M., Gottschalk C. W. Micropuncture study of glomerulotubular balance in the rat kidney. Nephron. 1969;6(3):418–436. doi: 10.1159/000179743. [DOI] [PubMed] [Google Scholar]
  3. Bank N., Koch K. M., Aynedjian H. S., Aras M. Effect of changes in renal perfusion pressure on the suppression of proximal tubular sodium reabsorption due to saline loading. J Clin Invest. 1969 Feb;48(2):271–283. doi: 10.1172/JCI105983. [DOI] [PMC free article] [PubMed] [Google Scholar]
  4. Barger A. C. Renal hemodynamic factors in congestive heart failure. Ann N Y Acad Sci. 1966 Nov 22;139(2):276–284. doi: 10.1111/j.1749-6632.1966.tb41202.x. [DOI] [PubMed] [Google Scholar]
  5. Brenner B. M., Bennett C. M., Berliner R. W. The relationship between glomerular filtration rate and sodium reabsorption by the proximal tubule of the rat nephron. J Clin Invest. 1968 Jun;47(6):1358–1374. doi: 10.1172/JCI105828. [DOI] [PMC free article] [PubMed] [Google Scholar]
  6. Brenner B. M., Berliner R. W. Relationship between extracellular volume and fluid reabsorption by the rat nephron. Am J Physiol. 1969 Jul;217(1):6–12. doi: 10.1152/ajplegacy.1969.217.1.6. [DOI] [PubMed] [Google Scholar]
  7. Brenner B. M., Falchuk K. H., Keimowitz R. I., Berliner R. W. The relationship between peritubular capillary protein concentration and fluid reabsorption by the renal proximal tubule. J Clin Invest. 1969 Aug;48(8):1519–1531. doi: 10.1172/JCI106118. [DOI] [PMC free article] [PubMed] [Google Scholar]
  8. Brunner F. P., Rector F. C., Jr, Seldin D. W. Mechanism of glomerulotubular balance. II. Regulation of proximal tubular reabsorption by tubular volume, as studied by stopped-flow microperfusion. J Clin Invest. 1966 Apr;45(4):603–611. doi: 10.1172/JCI105374. [DOI] [PMC free article] [PubMed] [Google Scholar]
  9. Buentig W. E., Earley L. E. Demonstration of independent roles of proximal tubular reabsorption and intratubular load in the phenomenon of glomerulotubular balance during aortic constriction in the rat. J Clin Invest. 1971 Jan;50(1):77–89. doi: 10.1172/JCI106486. [DOI] [PMC free article] [PubMed] [Google Scholar]
  10. Burg M. B., Orloff J. Control of fluid absorption in the renal proximal tubule. J Clin Invest. 1968 Sep;47(9):2016–2024. doi: 10.1172/JCI105888. [DOI] [PMC free article] [PubMed] [Google Scholar]
  11. Cohen M. L., Smith F. G., Jr, Mindell R. S., Vernier R. L. A simple, reliable method of measuring glomerular filtration rate using single, low dose sodium iothalamate I-131. Pediatrics. 1969 Mar;43(3):407–415. [PubMed] [Google Scholar]
  12. Cortney M. A., Mylle M., Lassiter W. E., Gottschalk C. W. Renal tubular transport of water, solute, and PAH in rats loaded with isotonic saline. Am J Physiol. 1965 Dec;209(6):1199–1205. doi: 10.1152/ajplegacy.1965.209.6.1199. [DOI] [PubMed] [Google Scholar]
  13. DE WARDENER H. E., MILLS I. H., CLAPHAM W. F., HAYTER C. J. Studies on the efferent mechanism of the sodium diuresis which follows the administration of intravenous saline in the dog. Clin Sci. 1961 Oct;21:249–258. [PubMed] [Google Scholar]
  14. DIRKS J. H., CIRKSENA W. J., BERLINER R. W. THE EFFECTS OF SALINE INFUSION ON SODIUM REABSORPTION BY THE PROXIMAL TUBULE OF THE DOG. J Clin Invest. 1965 Jul;44:1160–1170. doi: 10.1172/JCI105223. [DOI] [PMC free article] [PubMed] [Google Scholar]
  15. Earley L. E., Friedler R. M. Studies on the mechanism of natriuresis accompanying increased renal blood flow and its role in the renal response to extracellular volume expansion. J Clin Invest. 1965 Nov;44(11):1857–1865. doi: 10.1172/JCI105293. [DOI] [PMC free article] [PubMed] [Google Scholar]
  16. Earley L. E., Friedler R. M. The effects of combined renal vasodilatation and pressor agents on renal hemodynamics and the tubular reabsorption of sodium. J Clin Invest. 1966 Apr;45(4):542–551. doi: 10.1172/JCI105368. [DOI] [PMC free article] [PubMed] [Google Scholar]
  17. Earley L. E., Martino J. A., Friedler R. M. Factors affecting sodium reabsorption by the proximal tubule as determined during blockade of distal sodium reabsorption. J Clin Invest. 1966 Nov;45(11):1668–1684. doi: 10.1172/JCI105474. [DOI] [PMC free article] [PubMed] [Google Scholar]
  18. GIEBISCH G., KLOSE R. M., MALNIC G., SULLIVAN W. J., WINDHAGER E. E. SODIUM MOVEMENT ACROSS SINGLE PERFUSED PROXIMAL TUBULES OF RAT KIDNEYS. J Gen Physiol. 1964 Jul;47:1175–1194. doi: 10.1085/jgp.47.6.1175. [DOI] [PMC free article] [PubMed] [Google Scholar]
  19. Gertz K. H., Brandis M., Braun-Schubert G., Boylan J. W. The effect of saline infusion and hemorrhage on glomerular filtration pressure and single nephron filtration rate. Pflugers Arch. 1969;310(3):193–205. doi: 10.1007/BF00587209. [DOI] [PubMed] [Google Scholar]
  20. Gertz K. H., Braun-Schubert G., Brandis M. Zur Methode der Messung der Filtrationsrate einzelner nahe der Nierenoberfläche gelegener Glomeruli. Pflugers Arch. 1969;310(2):109–115. doi: 10.1007/BF00586768. [DOI] [PubMed] [Google Scholar]
  21. Gertz K. H., Mangos J. A., Braun G., Pagel H. D. On the glomerular tubular balance in the rat kidney. Pflugers Arch Gesamte Physiol Menschen Tiere. 1965 Sep 15;285(4):360–372. doi: 10.1007/BF00363236. [DOI] [PubMed] [Google Scholar]
  22. Hayslett J. P., Kashgarian M., Epstein F. H. Changes in proximal and distal tubular reabsorption produced by rapid expansion of extracellular fluid. J Clin Invest. 1967 Jul;46(7):1254–1263. doi: 10.1172/JCI105618. [DOI] [PMC free article] [PubMed] [Google Scholar]
  23. Hayslett J. P., Kashgarian M., Epstein F. H. Mechanism of change in the excretion of sodium per nephron when renal mass is reduced. J Clin Invest. 1969 Jun;48(6):1002–1006. doi: 10.1172/JCI106056. [DOI] [PMC free article] [PubMed] [Google Scholar]
  24. Hierholzer K., Wiederholt M., Stolte H. Hemmung der Natriumresorption im proximalen und distalen Konvolut adrenalektomierter Ratten. Pflugers Arch Gesamte Physiol Menschen Tiere. 1966;291(1):43–62. [PubMed] [Google Scholar]
  25. Horster M., Thurau K. Micropuncture studies on the filtration rate of single superficial and juxtamedullary glomeruli in the rat kidney. Pflugers Arch Gesamte Physiol Menschen Tiere. 1968;301(2):162–181. doi: 10.1007/BF00362733. [DOI] [PubMed] [Google Scholar]
  26. Howards S. S., Davis B. B., Knox F. G., Wright F. S., Berliner R. W. Depression of fractional sodium reabsorption by the proximal tubule of the dog without sodium diuresis. J Clin Invest. 1968 Jul;47(7):1561–1572. doi: 10.1172/JCI105848. [DOI] [PMC free article] [PubMed] [Google Scholar]
  27. Koch K. M., Aynedjian H. S., Bank N. Effect of acute hypertension on sodium reabsorption by the proximal tubule. J Clin Invest. 1968 Jul;47(7):1696–1709. doi: 10.1172/JCI105860. [DOI] [PMC free article] [PubMed] [Google Scholar]
  28. LEYSSAC P. P. Dependence of glomerular filtration rate on proximal tubular reabsorption of salt. Acta Physiol Scand. 1963 Jun-Jul;58:236–242. doi: 10.1111/j.1748-1716.1963.tb02644.x. [DOI] [PubMed] [Google Scholar]
  29. Landwehr D. M., Schnermann J., Klose R. M., Giebisch G. Effect of reduction in filtration rate on renal tubular sodium and water reabsorption. Am J Physiol. 1968 Sep;215(3):687–695. doi: 10.1152/ajplegacy.1968.215.3.687. [DOI] [PubMed] [Google Scholar]
  30. Lewy J. E., Windhager E. E. Peritubular control of proximal tubular fluid reabsorption in the rat kidney. Am J Physiol. 1968 May;214(5):943–954. doi: 10.1152/ajplegacy.1968.214.5.943. [DOI] [PubMed] [Google Scholar]
  31. Martino J. A., Earley L. E. Demonstraton of a role of physical factors as determinants of the natriuretic response to volume expansion. J Clin Invest. 1967 Dec;46(12):1963–1978. doi: 10.1172/JCI105686. [DOI] [PMC free article] [PubMed] [Google Scholar]
  32. Morel F., Murayama Y. Simultaneous measurement of undirectional and net sodium fluxes in microperfused rat proximal tubules. Pflugers Arch. 1970;320(1):1–23. doi: 10.1007/BF00588454. [DOI] [PubMed] [Google Scholar]
  33. Morgan T., Berliner R. W. In vivo perfusion of proximal tubules of the rat: glomerulotubular balance. Am J Physiol. 1969 Oct;217(4):992–997. doi: 10.1152/ajplegacy.1969.217.4.992. [DOI] [PubMed] [Google Scholar]
  34. Nakajima K., Clapp J. R., Robinson R. R. Limitations of the shrinking-drop micropuncture technique. Am J Physiol. 1970 Aug;219(2):345–357. doi: 10.1152/ajplegacy.1970.219.2.345. [DOI] [PubMed] [Google Scholar]
  35. Rector F. C., Jr, Brunner F. P., Seldin D. W. Mechanism of glomerulotubular balance. I. Effect of aortic constriction and elevated ureteropelvic pressure on glomerular filtration rate, fractional reabsorption, transit time, and tubular size in the proximal tubule of the rat. J Clin Invest. 1966 Apr;45(4):590–602. doi: 10.1172/JCI105373. [DOI] [PMC free article] [PubMed] [Google Scholar]
  36. Rector F. C., Jr, Sellman J. C., Martinez-Maldonado M., Seldin D. W. The mechanism of suppression of proximal tubular reabsorption by saline infusions. J Clin Invest. 1967 Jan;46(1):47–56. doi: 10.1172/JCI105510. [DOI] [PMC free article] [PubMed] [Google Scholar]
  37. Rodicio J., Herrera-Acosta J., Sellman J. C., Rector F. C., Jr, Seldin D. W. Studies on glomerulotubular balance during aortic constriction, ureteral obstruction and venous occlusion in hydropenic and saline-loaded rats. Nephron. 1969;6(3):437–456. doi: 10.1159/000179744. [DOI] [PubMed] [Google Scholar]
  38. SONNENBERG H., DEETJEN P. METHODE ZUR DURCHSTROEMUNG EINZELNER NEPHRONABSCHNITTE. Pflugers Arch Gesamte Physiol Menschen Tiere. 1964 Jan 30;278:669–674. [PubMed] [Google Scholar]
  39. STEINHAUSEN M., IRAVANI I., SCHUBERT G. E., TAUGNER R., BRAUN A., VON EGIDY, ROHMANN F. P., TAUGNER G. AUFLICHTMIKROSKOPIE UND HISTOLOGIE DER TUBULUSDIMENSIONEN BEI VERSCHIEDENEN DIURESEZUSTAENDEN. Virchows Arch Pathol Anat Physiol Klin Med. 1963 Aug 8;336:503–527. [PubMed] [Google Scholar]
  40. Schnermann J., Horster M., Levine D. Z. The influence of sampling technique on the micropuncture determination of GFR and reabsorptive characteristics of single rat proximal tubules. Pflugers Arch. 1969;309(1):48–58. doi: 10.1007/BF00592281. [DOI] [PubMed] [Google Scholar]
  41. Sonnenberg H., Solomon S. Mechanism of natriuresis following intravascular and extracelluar volume expansion. Can J Physiol Pharmacol. 1969 Feb;47(2):153–159. doi: 10.1139/y69-026. [DOI] [PubMed] [Google Scholar]
  42. Watson J. F. Effect of saline loading on sodium reabsorption in the dog proximal tubule. Am J Physiol. 1966 Apr;210(4):781–785. doi: 10.1152/ajplegacy.1966.210.4.781. [DOI] [PubMed] [Google Scholar]
  43. Windhager E. E., Lewy J. E., Spitzer A. Intrarenal control of proximal tubular reabsorption of sodium and water. Nephron. 1969;6(3):247–259. doi: 10.1159/000179732. [DOI] [PubMed] [Google Scholar]
  44. de Rouffignac C., Deiss S., Bonvalet J. P. Détermination du taux individuel de filtration glomérulaire des néphrons accessibles et inaccessibles à la microponction. Pflugers Arch. 1970;315(4):273–290. doi: 10.1007/BF00593456. [DOI] [PubMed] [Google Scholar]
  45. de Rouffignac C., Morel F. Etude par microdissection de la distribution et de la longueur des tubules proximaux dans le rein de cinq espèces de rongeurs. Arch Anat Microsc Morphol Exp. 1967 Apr-Jun;56(2):123–132. [PubMed] [Google Scholar]

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