Abstract
We tested the relationship between postglomerular microvascular protein concentration and rates of sodium and water transfer by rat proximal tubules. Using recently described microperfusion techniques, efferent arterioles and branch peritubular capillaries of normal hydropenic rats were perfused with colloid-free Ringer's solution, and isoncotic (9.0-10.0 g/100 ml) and hyperoncotic (15 g/100 ml) albumin-Ringer's solutions. Reabsorption in adjacent proximal tubules was studied using free-flow techniques, with initial collections obtained during normal blood perfusion, recollections during experimental microperfusion, and in some tubules, repeat recollections after microperfusion and spontaneous resumption of blood perfusion. Colloid-free perfusion resulted in a uniform inhibition of proximal reabsorption (absolute and fractional). Despite identical techniques, substitution of isoncotic and hyperoncotic perfusates resulted, on average, in unchanged and increased rates of reabsorption, respectively. These findings of direct linear changes in reabsorption in response to changes in postglomerular protein concentrations usually occurred in the absence of significant changes in filtered load, and were nearly always found to be reversible within minutes of cessation of experimental perfusion.
Given this evidence of a causal relationship between postglomerular oncotic pressure and proximal reabsorption, we undertook to determine whether this relationship is responsible for the parallel adjustments in proximal reabsorption that follow changes in GFR (glomerulotubular balance). Using a separate group of hydropenic rats, proximal reabsorption was studied, initially during partial aortic constriction (during which renal perfusion pressure, single nephron GFR, absolute proximal reabsorption, and calculated filtration fraction all were reduced below levels prior to constriction), and again while adjacent efferent arteriolar and peritubular capillary protein concentrations, but not GFR, were restored to normal (preconstriction) levels by microperfusion with 9-10 g/100 ml albumin-Ringer's solution. During this dissociation of GFR and postglomerular protein concentration, absolute and fractional proximal reabsorption nearly always increased in parallel with the changes in the latter, thereby demonstrating that glomerulotubular balance is mediated, at least in part, by changes in postglomerular oncotic pressure brought about by changes in filtration fraction.
Full text
PDF













Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- 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]
- BRESLER E. H. The problem of the volume component of body fluid homeostasis. Am J Med Sci. 1956 Jul;232(1):93–104. doi: 10.1097/00000441-195607000-00014. [DOI] [PubMed] [Google Scholar]
- Baldamus C. A., Hierholzer K., Rumrich G., Stolte H., Uhlich E., Ullrich K. J., Wiederholt M. Natriumtransport in den proximalen Tubuli und den Sammelrohren bei Variation der Natriumkonzentration im umgebenden Interstitium. Pflugers Arch. 1969;310(4):354–368. doi: 10.1007/BF00587244. [DOI] [PubMed] [Google Scholar]
- 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]
- 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]
- Brenner B. M., Galla J. H. Influence of postglomerular hematocrit and protein concentration on rat nephron fluid transfer. Am J Physiol. 1971 Jan;220(1):148–161. doi: 10.1152/ajplegacy.1971.220.1.148. [DOI] [PubMed] [Google Scholar]
- 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]
- CURRAN P. F., MACINTOSH J. R. A model system for biological water transport. Nature. 1962 Jan 27;193:347–348. doi: 10.1038/193347a0. [DOI] [PubMed] [Google Scholar]
- Diamond J. M., Bossert W. H. Standing-gradient osmotic flow. A mechanism for coupling of water and solute transport in epithelia. J Gen Physiol. 1967 Sep;50(8):2061–2083. doi: 10.1085/jgp.50.8.2061. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 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]
- 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]
- FUHR J., KACZMARCZYK J., KRUTTGEN C. D. Eine einfache colorimetrische Methode zur Inulinbestimmung für Nieren-Clearance-Untersuchungen bei Stoffwechselgesunden und Diabetikern. Klin Wochenschr. 1955 Aug 1;33(29-30):729–730. doi: 10.1007/BF01473295. [DOI] [PubMed] [Google Scholar]
- 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]
- LOWRY O. H., ROSEBROUGH N. J., FARR A. L., RANDALL R. J. Protein measurement with the Folin phenol reagent. J Biol Chem. 1951 Nov;193(1):265–275. [PubMed] [Google Scholar]
- 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]
- 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]
- Lowitz H. D., Stumpe K. O., Ochwadt B. Micropuncture study of the action of angiotensin-II on tubular sodium and water reabsorption in the rat. Nephron. 1969;6(3):173–187. doi: 10.1159/000179727. [DOI] [PubMed] [Google Scholar]
- 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]
- Morgan T., Berliner R. W. A study by continuous microperfusion of water and electrolyte movements in the loop of Henle and distal tubule of the rat. Nephron. 1969;6(3):388–405. doi: 10.1159/000179741. [DOI] [PubMed] [Google Scholar]
- 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]
- Nizet A. Influence of serumalbumin and dextran on sodium and water excretion by the isolated dog kidney. Pflugers Arch Gesamte Physiol Menschen Tiere. 1968;301(1):7–15. doi: 10.1007/BF00412414. [DOI] [PubMed] [Google Scholar]
- 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]
- Schnermann J., Levine D. Z., Horster M. A direct evaluation of the Gertz hypothesis on single rat proximal tubules in vivo: failure of the tubular volume to be the sole determinant of the reabsorptive rate. Pflugers Arch. 1969;308(2):149–165. doi: 10.1007/BF00587022. [DOI] [PubMed] [Google Scholar]
- Spitzer A., Windhager E. E. Effect of peritubular oncotic pressure changes on proximal tubular fluid reabsorption. Am J Physiol. 1970 Apr;218(4):1188–1193. doi: 10.1152/ajplegacy.1970.218.4.1188. [DOI] [PubMed] [Google Scholar]
- Steinhausen M., Eisenbach G. M., Galaske R. Countercurrent system in the renal cortex of rats. Science. 1970 Mar 20;167(3925):1631–1633. doi: 10.1126/science.167.3925.1631. [DOI] [PubMed] [Google Scholar]
- VOGEL G., HEYM E., ANDERSSOHN K. Versuche zur Bedeutung kolloidosmotischer Druckdifferenzen für einen passiven Transportmechanismus in der Nierenkanälchen. Z Gesamte Exp Med. 1955;126(5):485–495. [PubMed] [Google Scholar]
- VOGEL G., HEYM E. Untersuchungen zur Bedeutung kolloidosomotischer Druckdifferenzen für den Mechanismus der isosmotischen Flüssigkeitsresorption in der Niere. Pflugers Arch. 1956;262(3):226–232. doi: 10.1007/BF00369703. [DOI] [PubMed] [Google Scholar]
- Vereerstraeten P., Toussaint C. Effects of plasmapheresis on renal hemodynamics and sodium excretion in dogs. Pflugers Arch. 1969;306(1):92–102. doi: 10.1007/BF00586613. [DOI] [PubMed] [Google Scholar]
- Vereerstraeten P., Toussaint C. Mécanismes de l'excrétion du sodium par le rein du chien. Nephron. 1970;7(1):15–36. doi: 10.1159/000179805. [DOI] [PubMed] [Google Scholar]
- Vereerstraeten P., Toussaint C. Role of the peritubular oncotic pressure on sodium excretion by the avian kidney. Pflugers Arch. 1968;302(1):13–23. doi: 10.1007/BF00586779. [DOI] [PubMed] [Google Scholar]
- Vereerstraeten P., Toussaint C. Réduction de la natriurèse par la perfusion d'albumine dans la veine porte rénale du coq. Nephron. 1965;2(6):355–366. doi: 10.1159/000179417. [DOI] [PubMed] [Google Scholar]
- Vereerstraeten P., de Myttenaere M. Effect of raising the transtubular oncotic gradient on sodium excretion in the dog. Pflugers Arch. 1968;302(1):1–12. doi: 10.1007/BF00586778. [DOI] [PubMed] [Google Scholar]
- Vereerstraeten P., de Myttenaere M., Lambert P. P. Réduction de la natriurèse par la perfusion de protéines dans l'artère rénale du chien. Nephron. 1966;3(2):103–122. doi: 10.1159/000179451. [DOI] [PubMed] [Google Scholar]
- 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]
