Abstract
The experiments reported in this paper were designed to evaluate some of the characteristics of anion transport processes during fluid absorption from superficial proximal straight tubules isolated from rabbit kidney. We measured net chemical C1- flux during fluid absorption from tubules perfused and bathed with Krebs-Ringer buffers containing 113.6 mM C1-, 10 mM acetate, and 25 mM HCO-/3 at pH 7.4; assessed the effects of carbonic anhydrase inhibitors on net fluid absorption in the presence and absence of CO2; and evaluated the influx and efflux coefficients for [14C]-acetate transport at 37degreesC, at 21degreesC, and in the presence of carbonic anhydrase inhibitors. The experimental data shown that, for this nephron segment, net C1- flux accompanies approximately 27.5% of net Na+ absorption; and net C1- absorption may be accounted for by a passive transport process, primarily diffusional in nature. Fluid absorption in this nephron segment is reduced 40-60% by carbonic anhydrase inhibitors, but only when the tubules are exposed to 95% O2-5% CO2 rather than 100% O2. Thus, it seems probably that approximately half of Na+ absorption in these tubules may be rationalized in terms of a carbonic anhydrase-dependent CO2 hydration process. In addition, there may occur in these isolated proximal tubules an acetazolamide-insensitive moiety of HCO-/3 absorption comparable to that observed for proximal tubules in vivo. Finally, we provide evidence that net efflux of luminal acetate is due to metabolic energy-dependent processes other than CO2 hydration and may, under appropriate conditions, account for approximately one-fourth of net Na+ absorption.
Full text
PDFSelected References
These references are in PubMed. This may not be the complete list of references from this article.
- Barratt L. J., Rector F. C., Jr, Kokko J. P., Seldin D. W. Factors governing the transepithelial potential difference across the proximal tubule of the rat kidney. J Clin Invest. 1974 Feb;53(2):454–464. doi: 10.1172/JCI107579. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Burg M., Grantham J., Abramow M., Orloff J. Preparation and study of fragments of single rabbit nephrons. Am J Physiol. 1966 Jun;210(6):1293–1298. doi: 10.1152/ajplegacy.1966.210.6.1293. [DOI] [PubMed] [Google Scholar]
- Burg M., Green N. Effect of ethacrynic acid on the thick ascending limb of Henle's loop. Kidney Int. 1973 Nov;4(5):301–308. doi: 10.1038/ki.1973.121. [DOI] [PubMed] [Google Scholar]
- Burg M., Green N. Effect of mersalyl on the thick ascending limb of Henle's loop. Kidney Int. 1973 Oct;4(4):245–251. doi: 10.1038/ki.1973.110. [DOI] [PubMed] [Google Scholar]
- Burg M., Stoner L., Cardinal J., Green N. Furosemide effect on isolated perfused tubules. Am J Physiol. 1973 Jul;225(1):119–124. doi: 10.1152/ajplegacy.1973.225.1.119. [DOI] [PubMed] [Google Scholar]
- CLAPP J. R., WATSON J. F., BERLINER R. W. OSMOLALITY, BICARBONATE CONCENTRATION, AND WATER REABSORPTION IN PROXIMAL TUBULE OF THE DOG NEPHRON. Am J Physiol. 1963 Aug;205:273–280. doi: 10.1152/ajplegacy.1963.205.2.273. [DOI] [PubMed] [Google Scholar]
- Cardinal J., Lutz M. D., Burg M. B., Orloff J. Lack of relationship of potential difference to fluid absorption in the proximal renal tubule. Kidney Int. 1975 Feb;7(2):94–102. doi: 10.1038/ki.1975.14. [DOI] [PubMed] [Google Scholar]
- Frizzell R. A., Schultz S. G. Ionic conductances of extracellular shunt pathway in rabbit ileum. Influence of shunt on transmural sodium transport and electrical potential differences. J Gen Physiol. 1972 Mar;59(3):318–346. doi: 10.1085/jgp.59.3.318. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Frömter E., Diamond J. Route of passive ion permeation in epithelia. Nat New Biol. 1972 Jan 5;235(53):9–13. doi: 10.1038/newbio235009a0. [DOI] [PubMed] [Google Scholar]
- GOTTSCHALK C. W., LASSITER W. E., MYLLE M. Localization of urine acidification in the mammalian kidney. Am J Physiol. 1960 Mar;198:581–585. doi: 10.1152/ajplegacy.1960.198.3.581. [DOI] [PubMed] [Google Scholar]
- Grantham J. J., Irwin R. L., Qualizza P. B., Tucker D. R., Whittier F. C. Fluid secretion in isolated proximal straight renal tubules. Effect of human uremic serum. J Clin Invest. 1973 Oct;52(10):2441–2450. doi: 10.1172/JCI107435. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Grantham J. J., Qualizza P. B., Irwin R. L. Net fluid secretion in proximal straight renal tubules in vitro: role of PAH. Am J Physiol. 1974 Jan;226(1):191–197. doi: 10.1152/ajplegacy.1974.226.1.191. [DOI] [PubMed] [Google Scholar]
- Grantham J. J., Qualizza P. B., Welling L. W. Influence of serum proteins on net fluid reabsorption of isolated proximal tubules. Kidney Int. 1972 Aug;2(2):66–75. doi: 10.1038/ki.1972.73. [DOI] [PubMed] [Google Scholar]
- Höhmann B., Frohnert P. P., Kinne R., Baumann K. Proximal tubular lactate transport in rat kidney: a micropuncture study. Kidney Int. 1974 Apr;5(4):261–270. doi: 10.1038/ki.1974.35. [DOI] [PubMed] [Google Scholar]
- Imai M., Kokko J. P. Effect of peritubular protein concentration on reabsorption of sodium and water in isolated perfused proxmal tubules. J Clin Invest. 1972 Feb;51(2):314–325. doi: 10.1172/JCI106816. [DOI] [PMC free article] [PubMed] [Google Scholar]
- KEDEM O., KATCHALSKY A. A physical interpretation of the phenomenological coefficients of membrane permeability. J Gen Physiol. 1961 Sep;45:143–179. doi: 10.1085/jgp.45.1.143. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Kawamura S., Imai M., Seldin D. W., Kukko J. P. Characteristics of salt and water transport in superficial and juxtamedullary straight segments of proximal tubules. J Clin Invest. 1975 Jun;55(6):1269–1277. doi: 10.1172/JCI108046. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Kedem O., Leaf A. The relation between salt and ionic transport coefficients. J Gen Physiol. 1966 Mar;49(4):655–662. doi: 10.1085/jgp.49.4.655. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Kokko J. P., Burg M. B., Orloff J. Characteristics of NaCl and water transport in the renal proximal tubule. J Clin Invest. 1971 Jan;50(1):69–76. doi: 10.1172/JCI106485. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Kokko J. P. Proximal tubule potential difference. Dependence on glucose on glucose, HCO 3 , and amino acids. J Clin Invest. 1973 Jun;52(6):1362–1367. doi: 10.1172/JCI107308. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Kunau R. T., Jr The influence of the carbonic anhydrase inhibitor, benzolamide (CL-11,366), on the reabsorption of chloride, sodium, and bicarbonate in the proximal tubule of the rat. J Clin Invest. 1972 Feb;51(2):294–306. doi: 10.1172/JCI106814. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Lutz M. D., Cardinal J., Burg M. B. Electrical resistance of renal proximal tubule perfused in vitro. Am J Physiol. 1973 Sep;225(3):729–734. doi: 10.1152/ajplegacy.1973.225.3.729. [DOI] [PubMed] [Google Scholar]
- MUDGE G. H. Studies on potassium accumulation by rabbit kidney slices; effect of metabolic activity. Am J Physiol. 1951 Apr 1;165(1):113–127. doi: 10.1152/ajplegacy.1951.165.1.113. [DOI] [PubMed] [Google Scholar]
- Malnic G., Giebisch G. Symposium on acid-base homeostasis. Mechanism of renal hydrogenion secretion. Kidney Int. 1972 May;1(5):280–296. doi: 10.1038/ki.1972.41. [DOI] [PubMed] [Google Scholar]
- Malnic G., Mello Aires M. Microperfusion study of anion transfer in proximal tubules of rat kidney. Am J Physiol. 1970 Jan;218(1):27–32. doi: 10.1152/ajplegacy.1970.218.1.27. [DOI] [PubMed] [Google Scholar]
- Maren T. H. Carbonic anhydrase: chemistry, physiology, and inhibition. Physiol Rev. 1967 Oct;47(4):595–781. doi: 10.1152/physrev.1967.47.4.595. [DOI] [PubMed] [Google Scholar]
- RECTOR F. C., Jr, CARTER N. W., SELDIN D. W. THE MECHANISM OF BICARBONATE REABSORPTION IN THE PROXIMAL AND DISTAL TUBULES OF THE KIDNEY. J Clin Invest. 1965 Feb;44:278–290. doi: 10.1172/JCI105142. [DOI] [PMC free article] [PubMed] [Google Scholar]
- RECTOR F. C., Jr, SELDIN D. W., ROBERTS A. D., Jr, SMITH J. S. The role of plasma CO2 tension and carbonic anhydrase activity in the renal reabsorption of bicarbonate. J Clin Invest. 1960 Nov;39:1706–1721. doi: 10.1172/JCI104193. [DOI] [PMC free article] [PubMed] [Google Scholar]
- SCHACHTER D., MANIS J. G., TAGGART J. V. Renal synthesis, degradation and active transport of aliphatic acyl amino acids relationship to p-aminohippurate transport. Am J Physiol. 1955 Sep;182(3):537–544. doi: 10.1152/ajplegacy.1955.182.3.537. [DOI] [PubMed] [Google Scholar]
- Schafer J. A., Andreoli T. E. Cellular constraints to diffusion. The effect of antidiuretic hormone on water flows in isolated mammalian collecting tubules. J Clin Invest. 1972 May;51(5):1264–1278. doi: 10.1172/JCI106921. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Schafer J. A., Patlak C. S., Andreoli T. E. A component of fluid absorption linked to passive ion flows in the superficial pars recta. J Gen Physiol. 1975 Oct;66(4):445–471. doi: 10.1085/jgp.66.4.445. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Schafer J. A., Patlak C. S., Andreoli T. E. Osmosis in cortical collecting tubules. A theoretical and experimental analysis of the osmotic transient phenomenon. J Gen Physiol. 1974 Aug;64(2):201–227. [PMC free article] [PubMed] [Google Scholar]
- Schafer J. A., Troutman S. L., Andreoli T. E. Volume reabsorption, transepithelial potential differences, and ionic permeability properties in mammalian superficial proximal straight tubules. J Gen Physiol. 1974 Nov;64(5):582–607. doi: 10.1085/jgp.64.5.582. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Tune B. M., Burg M. B. Glucose transport by proximal renal tubules. Am J Physiol. 1971 Aug;221(2):580–585. doi: 10.1152/ajplegacy.1971.221.2.580. [DOI] [PubMed] [Google Scholar]
- Welling L. W., Grantham J. J. Physical properties of isolated perfused renal tubules and tubular basement membranes. J Clin Invest. 1972 May;51(5):1063–1075. doi: 10.1172/JCI106898. [DOI] [PMC free article] [PubMed] [Google Scholar]